We present a simple strategy to generate a family of carbon dot/iron oxide nanoparticles (C/Fe-NPs) that relies on the thermal decomposition of iron (III) acetylacetonate in the presence of a highly fluorescent carbon-rich precursor, while polyethylene glycol serves as the passivation agent. By varying the molar ratio of the reactants, a series of C/Fe-NPs have been synthesized with tuneable elemental composition in terms of C, H, O, N, Fe. The quantum yield is enhanced from 6% to 9% as the carbon content increases from 27% to 36%, while the room temperature saturation magnetization is improved from 4.1 emu/g to 17.7 emu/g as the iron content is enriched from 17 to 31%. In addition, the C/Fe-NPs show excellent antimicrobial properties, minimal cytotoxicity and demonstrate promising bioimaging capabilities, thus showing great potential for the development of advanced diagnostic tools.

Search for appropriate materials with favorable staggered energy band arrangements is important and of great challenge to fabricate Z-scheme photocatalysts with high activity in visible light. In this study, we demonstrated a facile and feasible strategy to construct highly active organic-inorganic Z-scheme hybrids (P-BMO) with linear pyrene-based conjugated polymer (P17-E) and Bi₂MoO₆ via in-situ palladium-catalyzed cross-coupling reaction. Characterization results revealed C-O chemical bond formed at the heterointerface between P17-E and Bi₂MoO₆ after in-situ polycondensation and endowed the hybrids with observably improved photogenerated carries transfer capability. Visible light driven photocatalytic removal of ciprofloxacin and Cr(VI) were significantly enhanced after the incorporation of P17-E into Bi₂MoO₆ whether with the morphology of nanosheets, nanobelts or microspheres. Moreover, this P-BMO hybrids were also found to exhibit sustainable excellent photocatalytic performance after four runs of photocatalytic evaluation test, suggesting its high activity and stability. To better eliminate the redox ability enhancement of P-BMO, a reasonable Z-scheme electrons transferring mechanism between P17-E and Bi₂MoO₆ was proposed and proved by the determination of •O₂^– and •OH and Pt nanoparticles photodeposition experiments. This work might provide a viable source and insight into the design of Z-scheme photocatalysts with excellent redox ability for environmental remediation.

Ferroelectric materials are crucial for today’s technological society, and nanostructured ferroelectric materials are important for downscaling of devices. Controlled and reproducible synthesis of these materials are therefore of immense importance. Hydrothermal synthesis is a well-established synthesis route, with a large parameter space for optimization, but a better understanding of nucleation and growth mechanisms is needed for full utilization and control. Here we use in situ X-ray diffraction to follow the nucleation and growth of BaTiO₃ formed by hydrothermal synthesis using two different titanium precursors, an amorphous titania precipitate slurry and a Ti-citric acid complex solution. Sequential Rietveld refinement was used to extract the time dependency of lattice parameters, crystallite size, strain and atomic displacement parameters. Phase pure BaTiO₃ nanoparticles 10 - 15 nm in size were successfully synthesized at different temperatures (100, 125, and 150 °C) from both precursors after reaction times ranging from a few seconds, to several hours. The two precursors resulted in phase pure BaTiO₃ with similar final crystallite size. Finally, two different growth mechanisms were revealed, where the effect of surfactants present during hydrothermal synthesis is discussed as one of the key parameters.

We fabricate large-area atomically thin MoS₂ layers through the direct transformation of crystalline molybdenum trioxide (MoO₃) by sulfurization at relatively low temperatures. The obtained MoS₂ sheets are polycrystalline (~10-20 nm single-crystal domain size) with areas of up to 300×300 µm² with 2-4 layers in thickness and show a marked p-type behaviour. The synthesized films are characterized by a combination of complementary techniques: Raman spectroscopy, X-ray diffraction, transmission electron microscopy and electronic transport measurements.

The emission of mercury (II) from coal combustion and other industrial processes continues to be a concern and have local impact on water resources. The detection of these ions in water with sensitive but rapid testing methods is desirable for environmental screening and fieldwork. Nanoparticles of various chemistries have shown promise for this purpose, as they can be used in simple colorimetric analyses. Silver nanoprisms were chemically synthesized resulting in a blue reagent solution, that transitioned towards yellow and colorless solutions when exposed to Hg²⁺ ions at various concentrations. A rapid galvanic reduction of Hg²⁺ onto the nanoprism surfaces is apparently responsible for a change in shape towards spherical nanoparticles, leading to the change in color. There were no interferences by other metal ions in solution, and pH had minimal effect in the range of 6.5 to 9.8. The silver nanoprism reagent provided a detection limit of approximately 0.5 µM (100 µg/L) for mercury (II), which compares favorably with other nanoparticle-based techniques. Further optimization may reduce this detection limit.

In this work we demonstrate the proof-of-concept of real-time discrimination between patches of serine or isoleucine monomers in the primary structure of custom-engineered, macro-dipole-like peptides, at uni-molecular level. We employed single-molecule recordings to examine the ionic current through the α-hemolysin (α-HL) nanopore, when hydrophilic serine or hydrophobic isoleucine residues, flanked by segments of oppositely charged arginine and glutamic amino acids functioning as a voltage-dependent ‘molecular brake’ on the peptide, were driven at controllable rates across the nanopore. The observed differences in the ionic currents blockades through the nanopore, visible at time resolutions corresponding to peptide threading through the α-HL’s constriction region, was explained by a simple model of the volumes of electrolyte excluded by either amino acid species, as groups of three serine or isoleucine monomers transiently occupy the α-HL. To provide insights into the conditions ensuring optimal throughput of peptide readout through the nanopore, we probed the sidedness-dependence of peptide association to and dissociation from the electrically and geometrically asymmetric α-HL.

Band-gap alignment engineering has now been extensively studied due to its high potential application. Here we demonstrate a simple route to synthesize two metal oxide layers and align them together according to their bandgaps on surface of crystalline silicon (c-Si) solar cells. The metal oxide layers can not only extend absorption spectrum to generate extra carriers but also serve to separate electron-hole pairs more efficiently. As a consequence, the photovoltaic performance of SnO₂/CdO /Si double-layer solar cell (DLSC) is highly improved compared to CdO/Si and SnO₂/Si single-layer solar cells(SLSCs) and SnO₂/CdO/Si double-layer solar cell (DLSC). By the alignment engineering, the SnO₂/CdO/Si DLSC produces a short circuit photocurrent (J_sc) of 38.20 mA/cm², an open circuit photovoltage (V_oc) of 0.575 V and a fill factor (FF) of 68.7%, corresponding to a light to electric power conversion efficiency (η) of 15.09% under AM1.5 illumination. These results suggest that with the use of metal oxide layers by band-gap alignment engineering, new avenues have been opened for developing high-efficiency and cost-effective c-Si solar cells.

Geopolymers are ecologically-friendly inorganic materials which can be produced at low temperatures from industrial wastes such as fly ash, blast furnace slags or mining residues. Although to date their principal applications have been as alternatives to Portland cement building materials, their properties make them suitable for a number of more advanced applications, including as photocatalytic nanocomposites for removal of hazardous pollutants from waste water or the atmosphere. For this purpose, they can be combined with photocatalytic moieties such as metal oxides with suitable bandgaps to couple with UV or visible radiation, or with carbon nanotubes or graphene. In these composites the geopolymers act as supports for the photoactive components, but geopolymers formed from wastes containing oxides such as Fe2O3 show intrinsic photoactive behaviour. This review discusses the structure and formation chemistry of geopolymers and the principles required for their utilisation as photocatalysts. The literature on existing photocatalytic geopolymers is reviewed, suggesting that these materials have a promising potential as inexpensive, efficient and ecologically-friendly candidates for the remediation of toxic environmental pollutants and would repay further development.

The size of TiO2 (either nanometric or micrometric) can significantly affect both its photocatalytic and photoelectrochemical properties, thus altering the photooxidation of organic pollutants in air or water. The purpose of this work is to give an account of the photoelectrochemical and photocatalytic features of some nano- and micro-sized TiO2 commercial powders towards a model reaction, the photooxidation of acetone. Cyclic voltammograms (CV) of TiO2 particulated electrodes under UV illumination experiments were carried out in either saturated O2 or N2 solutions for a direct correlation with the photocatalytic process. In addition, the effect of different reaction conditions on the photocatalytic efficiency under UV light in both aqueous and gaseous phases was also investigated. CV curves with the addition of acetone under UV light showed a negative shift of the photocurrent onset, confirming the efficient transfer of photoproduced reactive oxygen species (ROSs), e.g., hydroxyl radicals, or holes to acetone molecules. The photocatalytic experiments showed that the two nano-sized samples exhibit the best photocatalytic performance. The different photoactivity of the micro-sized samples is probably attributed to their morphological differences, affecting both the amount and distribution of free ROSs involved in the photooxidation reaction.

Metal oxide p-n heterojunction nanofibers (NFs) are among the most promising approaches to enhancing the efficiency of gas sensors. In this paper, we report the preparation of a series of p-NiO-loaded n-ZnO NFs, namely (1 − x) ZnO-xNiO (x = 0.03, 0.05, and 0.1 wt%), for hydrogen gas sensing experiments. Samples were prepared through the electrospinning technique followed by a calcination process. The sensing experiments showed that the sample with 0.05 wt% NiO loading resulted in the highest sensing performance at an optimal sensing temperature of 200 °C. The sensing mechanism is discussed in detail and contributions of the p-n heterojunctions, metallization of ZnO and catalytic effect of NiO on the sensing enhancements of an optimized gas sensor are analyzed. This study demonstrates the possibility of fabricating high-performance H₂ sensors through the optimization of p-type metal oxide loading on the surfaces of n-type metal oxides.

Different types of gold nanoparticles have been synthesized that great potential in medical applications such as medical imaging, bio-analytical sensing and photothermal therapy. However, their stability, polydispersity and biocompatibility are major issues of concern. For example, the synthesis of gold nanorods, obtained through the elongated micelle process, produce them with a high positive surface charge that is cytotoxic. While gold nanoshells are unstable and within a few weeks they decompose due to Ostwald ripening. In this work, we report the self-assembly of the capsid protein of cowpea chlorotic mottle virus (CCMV) around spherical gold nanoparticles, gold nanorods and gold nanoshells to form virus-like particles (VLPs). All gold nanoparticles were synthesized or treated to give them a negative surface charge, so they can interact with the positive N-terminus of the capsid protein leading to the formation of the VLPs. To induce the protein self-assembly around the negative gold nanoparticles, we use different pH and ionic strength conditions that were determined from the capsid protein phase diagram. The encapsidation with the viral capsid protein confers them better biocompatibility, stability, monodispersity and a new biological substrate on which one can introduce specific ligands towards particular cells, broadening the possibilities of medical application.

Oleylamine capped WS2 nanostructures were successfully formed at 320 °C via a relatively simple colloidal route. SEM and TEM analyses showed that the 3D nanoflowers that were initially formed disintegrated into 2D nanosheets after prolonged incubation. XPS and XRD analyses confirmed oxidation of WS2 into WO3. Sensors based on these oleylamine capped WS2 nanoflowers and nanosheets still showed a change in electrical response towards various concentrations of NH3 vapour at room temperature in a 25% relative humidity background despite the oxidation. The nanoflowers exhibited n-type response while the nanosheets displayed a p-type response towards NH3 exposure. The nanoflower based sensors showed better response to NH3 vapour exposure than the nanosheets. The sensors showed a good selectivity towards NH3 relative to acetone, ethanol, chloroform and toluene. Meanwhile, a strong interference of humidity to the NH3 response was displayed at high relative humidity levels. The results demonstrated that oleylamine limited the extent of oxidation of WS2 nanostructures. The superior sensing performance of the nanoflowers can be attributed to their hierarchical morphology which enhances the surface area and diffusion of the analyte.

Porous graphite was prepared without the use of template by rapidly heating the carbonization products from mixtures of anthracene, flourene, and pyrene with a CO₂ laser. Rapid CO₂ laser heating at a rate of 1.8 × 10 ⁶ °C/s vaporizes out the fluorene-pyrene derived pitch while annealing the anthracene coke. The resulting structure is that of graphite with 100 nm spherical pores. The graphitizablity of the porous material is the same as pure anthracene coke. Transmission electron microscopy revealed that the interface between graphitic layers and the pore walls are unimpeded. Traditional furnace annealing does not result in the porous structure as the heating rates are too slow to vaporize out the pitch, thereby illustrating the advantage of fast thermal processing. The resultant porous graphite was prelithiated and used as an anode in lithium ion capacitors. The porous graphite when lithiated had a specific capacity of 200 mAh/g at 100 mA/g. The assembled lithium ion capacitor demonstrated an energy density as high as 75 Wh/kg when cycled between 2.2 V to 4.2 V.

Magnetic iron oxide particles are used for in vitro diagnostics for nearly 40 years. Due to their unique physical, chemical, thermal and mechanical properties, as well as biocompatibility and low toxicity in the human body, iron oxide nanoparticles have been used in many biomedical applications, such as contrast agents for magnetic resonance imaging, carriers for controlled drug delivery and immunoassays, but also in magnetic hyperthermia. Our aim is to investigate the effect of pressure and temperature on the structural, thermal and magnetic properties of iron oxide nanomaterials prepared by hydrothermal synthesis. Iron oxide nanoparticles were synthesized at temperatures of 100-200°C and pressures of 20-1000 bar. It has been found that pressure influences the type of iron oxide crystalline phase. Thus, for lower pressure values (< 100 bar), iron oxide is predominantly formed as hematite, while at pressures > 100 bar, the major crystalline phase is goethite. The complex thermal analysis revealed the polymorphic changes of iron oxides at different temperatures. The existence of specific magnetite and hematite phases in all thermally treated samples are evidenced through the specific Verwey and Morin transitions highlighted by ZFC-FC (Zero Field Cooled-Field Cooled) measurements, whereas their relative content is precisely provided by Mössbauer spectroscopy.

There is great interest in developing biodegradable biopolymer-based packaging materials whose functional performance is enhanced by incorporating active compounds into them, such as light blockers, plasticizers, crosslinkers, diffusion blockers, antimicrobials, antioxidants, and sensors. However, many of these compounds are volatile, chemically unstable, water-insoluble, matrix incompatible, or have adverse effects on film properties, which makes them difficult to directly incorporate into the packaging materials. These challenges are being overcome by incorporating the bioactive compounds into nanoparticles, which are then introducing into the packaging materials. The presence of these nanoencapsulated active compounds in biopolymer-based coatings or films can greatly improve their functional performance. This article reviews the different kinds of nanocarriers available for loading active compounds into these types of materials, and then discusses their impact on the optical, mechanical, thermal, barrier, antioxidant, and antimicrobial properties of the packaging materials. Furthermore, this article highlights the different kinds of bioactive compounds that can be incorporated into biopolymer-based packaging.

A graphene-containing LDH was prepared by re-hydration of the oxides produced by the calcination of an organic LDH. While the memory effect is a widely recognized effect on oxides produced by inorganic LDHs, it is unprecedented from the calcination/re-hydration of organic ones. Different temperatures (400, 600 and 1100 °C) were tested, on the basis of thermogravimetric data. Water instead of a carbonate solution was used for the re-hydration, with CO₂ available from water itself and/or air to induce a slower process with an easier and better intercalation of the carbonaceous species within the layers. The samples were characterized by X-ray Powder Diffraction (XRPD), IR and Raman spectroscopy and scanning electron microscopy (SEM). XRPD indicate the presence of carbonate LDH mixed with a layered phase with a larger d-spacing. IR confirmed that the prevailing anion is carbonate, coming from the water used for the re-hydration and/or air. Raman data indicated the presence of low-ordered graphenic species moieties and SEM the absence of separated graphene of graphitic sheets, suggesting an intimate mixing of the carbonaceous phase with reconstructed LDH. Organic LDHs gave better memory effect after calcination at 400 °C. Conversely, the graphenic species are observed after rehydration of the sample calcined at 600 °C with a reduced memory effect, demonstrating the interference of the carbonaceous phase with LDH reconstruction and the bonding with LDH layers to form a graphene-LDH nanocomposite.

Curcumin is a promising anti-cancer drug but its applications in cancer therapy are limited due to its poor solubility, short half-life and low bioavailability. In this study, curcumin loaded magnetic alginate / chitosan nanoparticles were fabricated to improve the bioavailability, uptake efficiency and cytotoxicity of curcumin to MDA-MB-231 breast cancer cells. Alginate and chitosan were deposited on Fe3O4 magnetic nanoparticles based on their electrostatic properties. The sizes of the nanoparticles (120-200 nm) were within the optimum range for drug delivery. Sustained curcumin release was obtained use the nanoparticles with the ability to control the curcumin release rate by altering the number of chitosan and alginate layers. Confocal fluorescence microscopy results showed that targeted delivery of curcumin with the aid of magnetic field were achieved. The FACS assay indicated that MDA-MB-231 cells treated with curcumin loaded nanoparticles had a 3-6 folds uptake efficiency to those treated with free curcumin. MTT assay indicated that the curcumin loaded nanoparticles exhibited significantly higher cytotoxicity toward MDA-MB-231 cells than toward HDF cells. The sustained release profiles, enhanced uptake efficiency and cytotoxicity to cancer cells as well as the targeting potential make MACPs a promising candidate for cancer therapy.

A thorough study on the distribution of defect-related active energy levels has been performed on nanocrystalline TiO₂. Films have been deposited on thick-alumina printed circuit boards equipped with electrical contacts, heater and temperature sensors, to carry out a detailed thermally stimulated currents analysis on a wide temperature range (5-630K), in view to evidence contributions from shallow to deep energy levels within the gap. Data have been processed by numerically modelling electrical transport. The model considers both free and hopping contribution to conduction, a density of states characterized by an exponential tail of localized states below the conduction band and the convolution of standard TSC emissions with gaussian distributions to take into account the variability in energy due to local perturbations in the highly disordered network. Results show that in the low temperature range, up to 200K, hopping within the exponential band tail represents the main contribution to electrical conduction. Above room temperature, electrical conduction is dominated by free carriers contribution and by emissions from deep energy levels, with a defect density ranging within 10¹⁴ – 10¹⁸cm^-3, associated to physio- and chemi-sorbed water vapour,OH groups and to vacancy-oxygen defects.

In this research, atomistic molecular dynamics simulations are combined with mesoscopic phase-field computational methods in order to investigate phase-transformation in polycrystalline Aluminum microstructure. In fact, microstructural computational modeling of engineering materials could help to optimize their mechanical properties for industrial applications (e.g. directional solidification for turbine blades). As a result, a multiscale modeling approach is developed to find a relation between manufacturing variables (e.g. temperature) and microstructural properties of crystalline materials (e.g. grain size), which could be used to develop an advanced manufacturing process for sensitive applications. The results show that atomistic modeling of grain growth could be used as a first-principle approach in order to study phase transformation's kinetics, which could capture morphology of polycrystalline materials more accurately. On the other hand, phase-field mesoscopic approach needs less computational efforts, but still it relies on semi-empirical data to capture accurate phase transformation regimes, which makes this approach suitable for rapid examining of new manufacturing conditions as well as its effects on microstructural properties of polycrystalline materials.

Today is the era of nanoscience and nanotechnology, which finds applications in the field of medicine, electronics, or environmental cleanup. Even though the nanotechnology is in its emerging phase, but still it provides solutions to numerous challenges. Nanotechnology and nanoparticles are found very effective because of their unique chemical and physical properties, high surface area, but their high cost is one of the major hurdles in its wider application. So, the synthesis of nanomaterials especially 2D nanomaterials from the industrial, agricultural and other biological activities could provide a cost-effective technique. The nanomaterials synthesized from such waste not only minimizes the pollution but also provides an eco-friendly approach towards the utilization of the waste. In the present review work, the emphasis has been given on the types of nanomaterials, different methods for the synthesis of 2D nanomaterials from the waste generated from industries, agriculture and their application in electronics, medicine and catalysis.

In this paper, a kind of single-walled carbon nanotube nonlinear model is developed, and the strongly nonlinear dynamic characteristics of such carbon nanotubes subjected to random magnetic field are studied. The nonlocal effect of microstructure is considered based on the theory of nonlocal elasticity. The natural frequency of the strongly nonlinear dynamic system is obtained by the energy function method, the drift coefficient and the diffusion coefficient are verified. The stationary probability density function of the system dynamic response is given and the fractal boundary of the safe basin is provided. Theoretical analysis and numerical simulation show that stochastic resonance occurs when varying the random magnetic field intensity. The boundary of safe basin has fractal characteristics and the area of safe basin decreases when the intensity of the magnetic field permeability increases.

Breast cancer treatment mostly revolved around radiation therapy and surgical interventions, these treatments doesn’t provide satisfactory relief to the patients and carry unmanageable side-effects. Nanomaterials show promising results in treating cancer cells and have many advantages such as high biocompatibility, bioavailability and effective therapeutic capabilities. Interestingly, fluorescent magnetic nanoparticles have been used in many biological and diagnostic applications, but there is no report of use of fluorescent magnetic submicronic polymer nanoparticles (FMSP-nanoparticles) in the treatment of human breast cancer cells. In the present study, we have tested the effect FMSP-nanoparticles on human breast cancer cells (MCF-7). We have tested different concentrations (1.25µg/1mL, 12.5µg/mL and 50µg/1mL) of FMSP-nanoparticles in MCF-7 cells and evaluated the nanoparticles response morphometrically. Our results revealed that FMSP-nanoparticles produced a concentration dependent effect on the cancer cells, dose of 1.25µg/mL produced no significant effect on the cancer cell morphology and cell death, whereas dosages of 12.5µg/mL and 50µg/mL respectively showed significant nuclear augmentation, disintegration, chromatic condensation followed by dose dependent cell death. Our results demonstrate FMSP-nanoparticles have ability to induce cell death in MCF-7 cells and may be considered as a potential anti-cancer agent for breast cancer treatments.

Developing particles of different anisotropic shapes are the hot topic since decades as they guarantee some special features of properties not possible through other means. Again, controlling atoms to develop certain size and shape particle is a quite challenging job. In this study, gold particles of different shapes are developed via pulse-based electronphoton-solution interface process. Gold atoms of certain transition state develop monolayer assembly at solution surface around the light glow (known in argon plasma) being generated at bottom of copper capillary (known in cathode). The rate of uplifting gold atoms to solution surface is being controlled by forcing energy (travelling photons) pursuing electrons and high energy photons (in high density) entering to solution. Gold atoms dissociated from the precursor under dissipating heat energy into the solution supplied under propagating photons characteristic current through immersed graphite rod (known in anode). Placing packets of nano shape energy of tuned pulse protocol over compact monolayer assembly comprising transition state atoms develop tiny-sized particles of formed shape. On separation of joint tiny particles into two equilateral triangular-shaped tiny particles, exerting forces of surface format elongate atoms of one-dimensional arrays converting them into structures of smooth elements. Due to immersing level of force, such tiny-shaped particles pack from different zones at centre of light glow where they assembled structures of smooth elements for developing mono-layers of different shapes of particles. Developing one-dimensional particles deal assembling of structures of smooth elements of packing tiny-shaped particles from nearly rearward zones of reflection of north-south poles, whereas, developing multi-dimensional particles deal assembling of structures of smooth elements of packing tiny-shaped particles from the east-west poles and near regions. Depending on the number of assembled structures of smooth elements at point of nucleation, packing of tiny-shaped particles from different zones develop different shapes of the anisotropic particles. At fixed precursor concentration, increasing the process time results into develop particles of low aspect ratio. Under tuned parameters, developing mechanisms of particles exhibiting unprecedented features are discussed.

Research on the chemical mechanism and reciprocal behavior of the coronavirus relate to living organisms, engaging in the give and take of electrochemical mediators, is a very important, controversial and vital issue. What we should accept is the chemical identity of this scenario, and not preferably a characteristic of a biological system. This chemical reaction should be familiar, referring to the theory of chemical pathways involved in DNA/proteins in the body against aggressive guests (such as viruses). From the point of view of a chemist, this simple reaction is nothing more than an oxidation-reduction reaction (redox-stress signaling) which conducted and carried out by coronavirus in a biointerface medium. Thereby, oxidizing as well as reducing reagents should be very constructive, promoting development in such chemical process. We understand redox reactions as switchable thiol/disulfide exchanges (formation and cleavage of inherent disulfide bonds), then, we can hugely profit from redox-responsive nano-surfaces equipped with multiple new ionic and covalent interactions. This game-changing idea can substantiate by surface modified-nanoparticles to play powerful roles in synthesis of nano oxidizers as well as reducing agents in nanomedicine. Chemists and pharmacists must then explore new thoughts and present modern experiences/approaches of preparation nanoparticles and nanocomposites to create novel vaccines as well as coronavirus drugs. In this regard, this experience can also be so helpful for HIV/AIDS, which is caused by viruses.

The current research work illustrates an economic and rapid approach towards biogenic synthesis of silver nanoparticles using aqueous Punica granatum leaves extract (PGL-AgNPs). The optimization of major parameters involved in the biosynthesis process was done using Box-Behnken Design (BBD). The effects of different independent variables (parameters) namely concentration of AgNO3, temperature and ratio of extract to AgNO3on response viz. particle size and polydispersity index were analyzed. As a result of experiment designing, 17 reactions were generated which were further validated experimentally. The statistical and mathematical approaches were employed on these reactions in order to interpret the relationship between the factors and responses. The biosynthesized nanoparticles were initially characterized by UV-vis spectrophotometry followed by physicochemical analysis for determination of particle size, polydispersity index and zeta potential via dynamic light scattering (DLS), SEM and EDX studies. Moreover, the determination of functional group present in the leaves extract and PGL-AgNPs was done by FTIR. Antibacterial and antibiofilm efficacies of PGL-AgNPs against Gram-positive and Gram-negative bacteria were further determined. The physicochemical studies suggested that PGL-AgNPs were round in shape and of ~ 37.5 nm in size with uniform distribution. Our studies suggested that PGL-AgNPs exhibit potent antibacterial, and antibiofilm properties.

A series of Eu³⁺ doped CaSiO₃/SiO₂ nano-phosphor powder of controlled grain size, crystalline structure, and chemical composition were synthesized using the microemulsion technique. XRD profiles of samples sintered over 600 of suggested phase shift from amorphous powder grain to more ordered polycrystalline powder of triclinic type wollastonite, CaSiO₃, with preferred crystal phase orientation of (112) and tetragonal type cristobalites of SiO₂. The grain size, crystallinity, and chemical composition of the host matrix, activator and sensitizer strongly affected both the absorption and emission bands of these samples. The amplitude of both the orange and red emission bands significantly increased with sintering temperature. The emission band is red-shifted with decreasing grain sizes. These bands displayed good sensitivity to ionic concentration of the Si⁴⁺, Ca²⁺, and Eu³⁺. With increasing Ca²⁺ ion concentration both the intensity of the red photoluminescence (PL) band increased and a concentration quenching observed. Increase in Si⁴⁺ ion concentration led to quenching in PL intensity of both the orange and red bands whereas the amplitude of the blue-band slightly increased. With increasing Eu³⁺ ion concentration the red-band initially increased whereas it started decreasing at higher sample concentration. In the presence of Ca²⁺ ion as a sensitizer, the sample showed a remarkable PL property—including—about 100% photon conversion efficiency and a two-fold increase in excitation and emission photons.

Tin (IV) oxide nanoparticles (SnO2 NPs) have received a lot of interest because of their interesting features. SnO2 NPs have proven productive in a range of fields, including water purification, supercapacitors, batteries, antibacterial and antioxidant agents, and others. SnO2-based nanoparticles found a wide range of applications after incorporating materials with varying chemical compositions. SnO2 NPs and their nanocomposites have been used effectively as antibacterial agents against various pathogenic bacteria, photocatalysts for dye degradation, and electrode materials for supercapacitors (SCs). This article covers the characteristics of SnO2 NPs, SnO2 nanocomposite materials, applications of SnO2 NPs and their composite materials, including antibacterial, energy storage, and photocatalysis, as well as some significant recent studies.

The development of sensors for monitoring Carbon Monoxide (CO) in a large range of temperature is of crucial importance in areas as monitoring of industrial processes or personal tracking using smart objects. Devices integrating GaN/Ga₂O₃ core/shell nanowires (NWs) is a promising solution allowing combining the high sensitivity of the electronic properties to the states of GaN-core surface; and the high sensitivity to CO of Ga₂O₃-shell. Because the performances of sensors primarily depend on the material properties composing the active layer of the device, it is essential to control these properties and in first time its synthesis. In this work, we investigate the synthesis of GaN/Ga₂O₃ core-shell NWs with a special focus on the formation of the shell. The GaN NWs grown by Plasma-assisted molecular beam epitaxy, are post-treated following thermal oxidation to form Ga₂O₃-shell surrounding the GaN-core. We establish that the Ga₂O₃-shell thickness can be modulated from 1 up to 14 nm by changing the oxidation conditions, and follows the diffuse-controlled reaction. By combining XRD-STEM and EDX analysis, we also demonstrate that the oxide shell formed by thermal oxidation is crystalline and presents the β-Ga₂O₃ crystalline phase, and is synthesized in epitaxial relationship with the GaN-core.

Carbon nanotubes (CNTs) are effective supports for nano metals and together they represent hybrids that combine unique properties of both. A microwave induced reaction was used to deposit nano palladium on carboxylated and octadecylamine functionalized multiwall CNTs, which were used to carry out C-C coupling reactions in DMF and toluene. These hybrids showed excellent catalytic activity with yield as high as 99.8% while its enhancement with respect to commercially available Pd/C catalyst reached as high as 109%, and the reactions times were significantly lower. Polarity of the functionalized form was found to be a significant factor with the polar carboxylated CNT showing better activity in DMF while the relatively nonpolar octadecyl amine was better in toluene. The results suggest the possibility of tailor making functionalized CNT when used as catalyst supports

Graphene-oxide (G) was prepared by the Hummers’ method. A G-COOH layer was synthesised using chloroacetic acid and G. To fabricate carboxylated graphene-RuO2 (G-COORu) nano¬¬-composites, RuO2 nano particles were grown on graphene layers using a one-step thermal method, -COOH(G-COOH), and RuCl3. All materials were characterised using X-ray diffraction, transmission electron microscopy, scanning electron microscopy, 13C-nuclear magnetic resonance as well as X-ray photoelectron, Fourier-transform infrared spectroscopy, and Raman. The electrochemical characteristics of the G-COORu supercapacitors were analysed using electrochemical impedance spectroscopy, cyclic voltammetry, constant current charge–discharge tests, and Nyquist impedance plots. The supercapacitors exhibit a specific capacitance of ~125 F g-1 at 100 mA cm-2 within the potential range of 0–1.0 V. The method used here provides a simple approach for the deposition of RuO2 nano particles on graphene layers and can be widened to the fabrication of other classes of hybrids based on G layers for specific technical applications.

Abstract: Tumor-targeting and blood-brain barrier (BBB)-penetrating are highly desirable for the treatment of glioma. In this study, we developed Pep-1&borneol-bifunctionalized carmustin-loaded micelles (Pep-1/Bor/CMS-M) capable of targeting to IL-13 receptor-overexpressed glioma and penetrating the brain microvascular endothelial cells-associated physiologic barriers. Pep-1/Bor/CMS-M were nearly spherical particles with a dimeter of 32.6 ± 1.1 nm and zeta potential of -21.3 ± 3.1 mV. Carmustine (CMS) released from Pep-1/Bor/CMS-M in pH 7.4 was significantly faster than in acidic environments. In human glioma BT325 cellular studies, Pep-1/Bor/CMS-M remarkably increased the cytotoxicity, notably improved the internalization and effectively induced the cell apoptosis. Likewise, in human brain microvascular endothelial cells (HBMEC) cells, Pep-1/Bor/CMS-M obviously promoted the cellular uptake, rapidly decreased the transepithelial electrical resistance (TEER) and thereby of enhancing the ability of penetration. In orthotopic Luc-BT325 glioma tumor-bearing nude mouse models, the stronger fluorescence signal and longer retention were observed in brain tissues compared with other controls, after single administration of DiD-labelled Pep-1/Bor/M (DiD/Pep-1/Bor/M). Importantly, Pep-1/Bor/CMS-M displayed the strongest inhibition of tumor growth, the longest survival period and low systemic toxicity in treating orthotopic glioma tumor-bearing nude mice. Simultaneous functionalization of Pep-1 and borneol offers a novel strategy for designing CMS-based nanomedicine and precisely treating glioma.

Microplastics (MPs) and nanoplastics (NPs) are distributed and transferred among the four major environmental compartments (air, water, soil, and biota) and have been already found in humans, making crucial to develop remediation technologies to tackle this kind pollution. Photocatalysis can be used to eliminate MPs present in contaminated wastewater effluents before their discharge into waterbodies. In this work, several green TiO2-based semiconductors were prepared using the extrapallial fluid (EPF) of Mytilus edulis sea water mussels as doping precursor. The semiconductors were then used as films or powders to photocatalytically degrade polystyrene (PS) NPs and MPs and polyethylene (PE) MPs. It was found that the obtention of green TiO2-based semiconductors with good characteristics for photocatalytic purposes (anatase crystalline phase, presence of porosity, activity in visible light and high surface area) seems not enough to achieve high degradation efficiency. The operational conditions of the reaction system should be also taken into account. For instance, the convenience of using semiconductors in the form of films can be overcome by their limited exposed surface area or the null adsorption of the semiconductor in the MPs particles. Additionally, crystallinity of the semiconductor can be a more determinant factor to take into account when performing photocatalysis of MPs.

This work shows the results obtained in the synthesis of srilankite nanoparticles, (Zr, Ti)O2, and TiO2 anatase, both catalysts presented an admix of phases, anatase/rutile, and srilankite/rutile, respectively. Their performance in the production of biodiesel through the esterification of oleic acid was evaluated. The catalysts were obtained using the sol-gel process and sulfated via the impregnation method. The samples were characterized using X-ray diffraction (XRD), scan electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and Fourier-Transform Infrared Spectroscopy (FTIR) to analyze the properties in its crystalline structure, morphology, and chemical composition. Its efficiency during the esterification reaction was measured based on the decrease in free fatty acids (FFA). FFA, oleic acid was added at different weight percentages (1%, 3%, and 5% w/w). The time of reaction was 6 hours at 55 °C and the catalyst with better performance was the sulfated Srilankite/rutile, reaching a maximum conversion of up to 90%.

The invention of nanoscience not only brings a revolutionary change in the field of science but also changed the direction of research. Today the whole world is under the trigger of nano and nanoparticles have multidimensional applications in every aspect of life including environmental point of view. Till today a plethora of nanoparticles have been synthesized and have also been applied for multiple purposes and hence grabbed the attention of researchers all over the world. Among the bunch of NPs discovered to date, we have a particular interest in silver nanoparticles (AgNPs) because of their cost-effectiveness and huge abundance in the earth’s crust. With respect to every passing day, due to various kinds of anthropological activities, the quality of the environment such as air, water and soil is depleting which ultimately hampers the human civilization. To encompass the growing environmental issues, many techniques have been adopted. Among the many strategies, tackling the current issues regarding environment through nanoscience is highly worthy as because of its cost-effectiveness, less time consuming and easy handling process. This article reviews the potential of nanoparticles, particularly silver nanoparticles, for a wide range of environmental applications, such as soil, air, and water remediation.

Sub-micron o/w emulsions coated with chitosan have been used for drug delivery, quorum sensing inhibition and vaccine development. To study interactions with biological systems, nanocapsules have been fluorescently labelled in previous works, but it is often difficult to distinguish the released label from intact nanocapsules. In this study, we present advanced labelling strategies based on FRET measurements for chitosan-coated nanocapsules and investigate their dissolution and degradation. We used FRET measurements of nanocapsules loaded with equimolar concentrations of two fluorescent dyes in their oily core and correlated them with DLS count rate measurement and absorbance measurements during their disintegration by dissolution. Using count rate measurements, we also investigated the enzymatic degradation of nanocapsules using pancreatin and how protein corona formation influences their degradation. Of note, nanocapsules dissolved in ethanol, where FRET decreased simultaneously with count rate, and absorbance caused by nanocapsule turbidity, indicating increased distance between dye molecules after their release. Nanocapsules were degradable by pancreatin in a dose dependent manner, and showed a delayed enzymatic degradation after protein corona formation. We present here novel labelling strategies for nanocapsules that allow us to judge their status and an in vitro method to study nanocapsule degradation and the influence of surface characteristics.

Tantalum doped ZnO structures (ZnO:Ta) were synthesized and some of their characteristics were studied. ZnO material was deposited on silicon substrates by using a hot filament chemical vapor deposition (HFCVD) reactor. The raw materials were a pill made of a mixture of ZnO and Ta₂O₅ powders, and molecular hydrogen was used as a reactant gas. Percentage of tantalum was varied from 0 to 500 mg by varying the percentage of tantalum oxide in the mixture of the pill source, by holding a fixed amount of 500 mg of ZnO in all experiments. X-ray diffractograms confirmed the presence of zinc oxide in the wurtzite phase and metallic zinc with a hexagonal structure, and no other phase was detected. Displacements to lower angles of reflection peaks, compared with those from samples without contamination, were interpreted as the inclusion of the Ta atoms in the matrix of the ZnO. This fact was confirmed by EDS and XRD measurements. From SEM images from undoped samples exhibited mostly micro sized semi-spherical structures while doped samples displayed a trend to grown as nanocrystalline rods. The presence of tantalum during the synthesis affects the way of the growth. Green photoluminescence at naked eye was observed when Ta doped samples were illuminated by ultraviolet radiation and confirmed by PL spectra. PL intensity on Ta doped ZnO varied from those undoped samples up to 8 times.

To achieve efficient and durable consolidation of weathered sandstone, the selection of a suitable consolidant is essential. To reasonably assess the suitability of different formulations, it is fundamental to compare their performance as a consolidant within a substrate, which reliably models the properties of deteriorated material. As a test substrate, the sandstone from quarries in Mšené in central Bohemia was selected, for its developed porosity and relatively low mechanical strength. To obtain relevant comparison of their application potential, both commercial (Remmers KSE OH and Surfapore) and self-developed consolidants were included. To test the long-term stability of each consolidant, the stone was subjected to accelerated weathering. The characterization of texture properties was based on the physical sorption of nitrogen and krypton, mercury intrusion porosimetry and water uptake. While the mechanical properties in microscale were determined by nanoindentation, the mechanical strength in macroscale before and after consolidation was measured by drilling resistance. Both commercial exhibited good mechanical performance with reasonable durability. The performance of our developed samples was comparable or, in some cases, superior. Very interesting were the consolidants containing TiO2 and ZnO nanoparticles, the former exhibiting comparable degree of consolidation and durability as commercial ones, with additional photocatalytic function, the latter unusually high increase in the mechanical strength, even after the weathering test. The diammonium hydrogen phosphate based consolidant showed exceptional durability in the weathering test, which makes it a promising product not only for carbonate but also sandstone materials.

The purpose of this study was to investigate the effect of chitosan (CS) and Alginate (Alg) polymers concentrations and CaCl2 concentration on metronidazole (MET) drug loading (LE), size particles and zeta potential. Nanocomposites were prepared by ionotropic pregelation method. A (21 *31 *21) *3= 36 full factorial design (FFD) was used to predict statistical equation and responses. The MET-CS-AlgNPs nanocomposites were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, thermal gravimetric analysis, scanning electron microscope and in vitro drug release studies. All data indicated the presence of drug into MET-CS-AlgNPs nanocomposites. The release profile of MET-CS-AlgNPs nanocomposites was found to be sustained

Malignant melanoma is a highly aggressive type of cancer that requires radical treatment strategies to inhibit the cancer cell progression and metastasis. In recent years, preclinical research and clinical trials on melanoma treatment are considerably focused on the adjuvant-based immunotherapy for enhancing the immune response of innate immune cells against cancer cells. However, the clinical outcome of these adjuvant-based treatments are inadequate due to improper delivery system for these immune activators to reach the target site. Hence, we developed a vaccine formulation containing tumor lysate protein (TL) and poly I:C (PIC) complexed with positively charged poly (sorbitol-co- polyethylenimine (PEI)(PSPEI). The resulting ionic PSPEI-polyplexed antigen/adjuvant (PAA) (PSPEI-PAA) nanocomplexes were stable at the physiological condition, non-toxic and enhanced intracellular uptake in immature dendritic cells. In murine B16F10 tumor xenograft model, PSPEI-PAA nanocomplexes significantly suppressed tumor growth and did not exhibit any noticeable sign of toxicity. Additionally, the cytotoxic T lymphocytes (CTLs) assay involving co-culturing of splenocytes isolated from the PSPEI-PAA-treated mice with that of B16F10 cells significantly revealed enhanced cancer killing by the TL-reactivated CTLs compared to untreated control mice bearing tumor. Therefore, we strongly believe that PSPEI-PAA nanocomplexes could be an efficient antigen/adjuvant delivery system and also enhance the antitumor immune response against melanoma tumor in the future clinical trials.

The three-point bending behavior of a single Au nanowire deformed with an atomic force microscope was monitored by coherent X-ray diffraction using a sub-micrometer sized hard X-ray beam. While three-dimensional reciprocal-space maps were recorded before and after deformation by standard rocking curves, they were measured by scanning the energy of the incident X-ray beam during deformation at different loading stages. The mechanical behavior of the nanowire is visualized in reciprocal space and a complex deformation mechanism is described. In addition to the expected bending of the nanowire, torsion is detected. Bending and torsion angles are quantified from the high resolution diffraction data.

The potential of sodium alginate (ALG) and gum arabic (GA) as wall polymers for L-ascorbic acid (AA) encapsulation as a tool for their preservation against the thermo-oxidative degradation was investigated. The influence of such polymers used as wall material on the AA-content, size, encapsulation efficiency, encapsulation yield and thermo-oxidative stability were evaluated. The AA-microparticles were obtained using the spray-drying technique. An experimental Taguchi design was employed to assess the influence of the variables in the encapsulation process. The microparticles morphology and size distribution were characterized by scanning electron microscopy and laser diffraction. The thermal stability of AA microparticles was studied by differential scanning calorimetry and thermogravimetry analysis. This work points out the viability to encapsulate AA using GA and ALG through a spray-drying process. In general, a product yield ranging from 35.1% to 83.2% and an encapsulation efficiency above 90% was reached. Spherical microparticles with a smooth surface were obtained with a mean diameter around 6 μm and 9 μm for the those prepared with GA and ALG, respectively. The thermo-oxidative analysis showed that both polymers allow maintaining AA stable up to 188 °C, which is higher than the traditional processing temperature used in the fish feed industry.

The development of a highly specific drug delivery system (DDS) for anti-cancer therapeutics is an area of intense research focus. Chemical engineering of a “smart” DDS to specifically target tumor cells has gained interest, designed for safer, more efficient, and effective use of chemotherapeutics for the treatment of cancer. However, the selective targeting and choosing the critical cancer surface biomarker are essential for targeted treatments to work. The folic acid receptor alpha (FRalpha) has gained popularity as a potential target in triple-negative breast cancer (TNBC). We have previously reported on a functionalized folic acid (FA)-conjugated amphiphilic alternating copolymer poly(styrene-alt-maleic anhydride) (FA-DABA-SMA) via a biodegradable linker 2,4-diaminobutyric acid (DABA) that has the essential features for efficient “smart” DDS. This biocompatible DDS self-assembles in a pH-dependent manner, providing stimuli-responsive, active targeting, extended-release of hydrophobic chemotherapeutic agents, and can effectively penetrate the inner core of 3-dimensional cancer spheroid models. The empty FA-DABA-SMA decreased spheroid volume, revealing a previously unknown mechanism of action. Upon further investigation, a size- and shape-dependent interaction FA-DABA-SMA with FR reduced the expression of p53, the product of the highly mutated TP53 gene, and additional oncogenic c-Myc and STAT3 proteins. Here, we investigated how this copolymer influences FR behavior and disrupting the receptor’s functions. Results indicate that FA-DABA-SMA increases FR expression levels in breast MDA MB-231 cancer cells and disrupting FR signaling by the reduction in HES1 and NOTCH1 protein expression levels. Also, FA-DABA-SMA induces apoptosis and further causes a change in the morphology of the MDA MB-231 cells, as well as significantly reduces their ability to migrate in a Scratch wound assay. Collectively, these findings provide a novel insight into the functionalized FA-DABA-SMA copolymer. The 350 kDa and 20 kDa copolymers actively target FRα to initialize internationalization. However, only the large size and sheet-shaped 350 kDa copolymers disrupt FRα signaling. The significance of these novel findings reveals the intracellular activity of the copolymer that is critically dependent on the size and structural shape. This report offers novel therapeutic insight into a dual mechanism of FA-DABA-SMA copolymer for its therapeutic potential for the treatment of cancer.

Perovskite type (Pb1-1.5x Lax0.5x)TiO3 (PLT) ceramics with x = 0.21, 0.22, 0.23, 0.24, 0.25 were prepared by the sol-gel method. Their structural, optical, and dielectric properties were investigated. The crystallite compounds were obtained by calcinating the mixture of PbCO3, TiO2, and La2O3 at 1000ºC for different time periods. After 4 h annealing, PLT23 sample, no secondary phases have been observed in the XRD spectrum of the PLT sample with 23% La content (PLT23). This sample appears to be notably distinguished in its structural, optical, and dielectric characteristics compared with other samples.

This is the second of a two-paper series describing a multi-scale modeling approach developed to simulate crack sensing in polymer fibrous composites by exploiting interruption of electrically conductive carbon nanotube (CNT) networks. The approach is based on the finite element (FE) method. FE models at three different scales, namely the micro-scale, the meso-scale and the macro-scale, have been developed using the ANSYS PDL environment. In the present paper, the meso- and macro-scale analyses are described. In the meso-scale, a two-dimensional model of the CNT/polymer matrix reinforced by carbon fibers is used to develop a crack sensing methodology from a parametric study which relates the crack position and length with the reduction of current flow. In the meso-model, the effective electrical conductivity of the CNT/polymer computed from the micro-scale is used as input. In the macro-scale, the final implementation of the crack sensing methodology is performed on a CNT/polymer/carbon fiber composite volume using as input the electrical response of the cracked CNT/polymer derived at the micro-scale and the crack sensing methodology. Analyses have been performed for cracks of two different lengths. In both cases, the numerical model predicts with good accuracy both the length and position of the crack. These results highlight the prospect of conductive CNT networks to be used as a localized structural health monitoring technique.

Suppressing the charge recombination at the interface of photoanode/electrolyte is the crucial way to enhance the photovoltaic performance of quantum dot sensitized solar cells (QDSSCs). In this scenario, ZnS/SiO2 blocking layer was deposited on TiO2/CuInS2 QDs to inhibit the charge recombination at photoanode/electrolyte interface. As a result, the TiO2/CuInS2/ZnS/SiO2 based QDSSCs delivers a power conversion efficiency (η) value of 4.63%, which is significantly higher than the 2.15% and 3.23% observed for QDSSCs with a TiO2/CuInS2 device and TiO2/CuInS2/ZnS, respectively. Electrochemical impedance spectroscopy and open circuit voltage decay analyses indicate that ZnS/SiO2 passivation layer on TiO2/CuInS2 suppress the charge recombination at the photoanode/electrolyte interface and prolongs the electron lifetime.

In this paper a novel type of a highly sensitive gas sensor device based on the surface photovoltage effect is described. The developed surface photovoltage gas sensor is based on a reverse Kelvin probe approach. As the active gas sensing electrode the porous ZnO nanostructured thin films are used deposited by the direct current (DC) reactive magnetron sputtering method exhibiting the nanocoral surface morphology combined with an evident surface nonstoichiometry related to the unintentional surface carbon and water vapor contaminations. Among others, the demonstrated SPV gas sensor device exhibits a high sensitivity of 1 ppm to NO₂ with a signal to noise ratio of about 50 and a fast response time of several seconds under the room temperature conditions.

Polymer composites with high thermal conductivity have a great potential for applications in modern electronics due to their low cost, easy process, and stable physical and chemical properties. Nevertheless, most polymer composites commonly possess unsatisfactory thermal conductivity, primarily because of the high interfacial thermal resistance between inorganic fillers. Herein, we developed a novel method through silver functionalized graphene nanosheets (GNS) and multiwalled carbon nanotube (MWCNT) composites with excellent thermal properties to meet the requirements of thermal management. The effects of composites on interfacial structure and properties of the composites were identified, and the microstructures and properties of the composites were studied as a function of the volume fraction of fillers. An ultrahigh thermal conductivity of 12.3 W/mK for polymer matrix composites was obtained, which is an approximate enhancement of 69.1 times compared to the polyvinyl alcohol (PVA) matrix. Moreover, these composites showed more competitive thermal conductivities compared to untreated fillers/PVA composites applied to the desktop central processing unit, making these composites a high-performance alternative to be used for thermal management.

Plasmonic gold nanorods play important roles in nowadays state-of-the-art plasmonic sensing techniques. Most of the previous studies and applications focused on gold nanorods with relatively small aspect ratios, where the plasmon wavelengths are smaller than 900 nm. Gold nanorods with large aspect ratios are predicted to exhibit high refractive-index sensitivity (Langmir 2008, 24, 5233–5237.), which therefore should be promising for developing of high-performance plasmonic chemical- and bio-sensors. In this study, we developed gold nanorods with aspect ratios over 7.9, which exhibit plasmon resonances around 1064 nm. The refractive index (RI) sensitivity of these nanorods have been evaluated by varying their dielectric environment, whereby a sensitivity as high as 473 nm/RIU can be obtained. Furthermore, we have demonstrated the large-aspect-ratio nanorods as efficient substrate for surface enhanced Raman spectroscopy (SERS), where an enhancement factor (EF) as high as 9.47×10⁸ was measured using 4-methylbenzenethiol (4-MBT) as probe molecule. Finally, a type of flexible SERS substrate is developed by conjugating the gold nanorods with the polystyrene (PS) polymer. The results obtained in our study can benefit the development of plasmonic sensing techniques utilized in the near-infrared spectral region.

Rapid progress in the development of highly efficient nanoparticle-based construction technologies has not always been accompanied by a corresponding understanding of their effects on human health and ecosystems. Here, we compare toxicological effects of pristine TiO₂, ZnO and SiO₂, and coated SiO₂ nanoparticles and evaluate their suitability as additives to consolidants of weathered construction materials. First, WST-1 and LDH assays were used to determine the viability of human alveolar A549 cells at various nanoparticle concentrations (0–250 μg mL⁻¹). While the pristine TiO₂ and coated SiO₂ nanoparticles did not exhibit any cytotoxic effect up to the highest tested concentration, the pristine SiO₂ and ZnO nanoparticles significantly reduced cell viability. Second, as all the developed nanoparticle-modified consolidants increased the mechanical strength of weathered sandstone, the decisive criterion for the selection of the most suitable nanoparticle additive was as low toxicity as possible. We believe that this approach will be of high importance for industry to identify materials representing top functional properties and low toxicity at an early stage of the product development.

The high hydrophobicity of fullerenes and the resulting formation of aggregates in aqueous solutions hamper the possibility of their exploitation in many technological applications. Noncovalent bioconjugation of fullerenes with proteins is an emerging approach for their dispersion in aqueous media. Contrary to covalent functionalization, bioconjugation preserves the physicochemical properties of the carbon nanostructure. The unique photophysical and photochemical properties of fullerenes are then fully accessible for applications in nanomedicine, sensoristic, biocatalysis and materials science fields. However, proteins are not universal carriers. Their stability depends on the biological conditions for which they have evolved. Here we present two model systems based on pepsin and trypsin. These proteins have opposite net charge at physiological pH. They recognize and disperse C₆₀ in water. UV-Vis spectroscopy, zeta-potential and atomic force microscopy analysis demonstrates that the hybrids are well dispersed and stable in a wide range of pH’s and ionic strengths. A previously validated modelling approach identifies the protein-binding pocket involved in the interaction with C₆₀. Computational predictions, combined with experimental investigations, provide powerful tools to design tailor-made C₆₀@proteins bioconjugates for specific applications.

Owing to their extraordinary properties, carbon-based nanomaterials are gaining traction in biomedicine. Green synthesis is the cost-effective method for fabricating carbon-based nanomaterials due to its rapidity, renewable nature, and sustainability. This study emphasis on the graphene oxide (GO) reduction using a simple one-pot technique that does not require the use of toxic reducing agents. This article reports the green synthesis of reduced graphene oxide (RGO) using Hibiscus sabdariffa L. calyxes extract as the natural reducing agent. Additionally, this article also provides analysis RGO using X-ray diffraction (XRD), UV-Visible spectroscopy (UV-Vis), and Raman spectroscopy. XRD result showed that the GO peak at 11o diminished, and a new hump appear at 22o indicating that the GO is fully reduced when it is refluxed for 6 hours, at 100oC with 1:3 ratio of GO:PE. The UV-Vis data indicated absorption peak of GO (237 nm) and RGO (265 nm) at distinct locations. This finding shed new light on the enormous potential of Hibiscus sabdariffa L. calyxes extract for green GO reduction. As a result, this environmentally friendly method can help reduce dependence on chemical materials.

Ucuùba fat is fat obtained from a plant found in South America, mainly in Amazonian Brazil. Due to its biocompatibility and bioactivity, the Ucuùba fat was used for production of ketoconazole-loaded nanostructured lipid carriers (NLC) in view of an application for the treatment of onychomycosis and other persistent fungal infections. The development and optimization of the Ucuùba fat based NLC were performed using a Box-Behnken design of experiment. The independent variables were surfactant concentration (% w/v), liquid lipids concentration (% w/v), solid lipids concentration (% w/v), while the outputs of interest were particle size, polydispersity index (PDI) and drug encapsulation efficiency (EE). The Ucuùba fat based NLC were produced and the process optimized determining a predictive mathematical model. Applying the model, two formulations with the pre-required particle size, i.e., 30 and 85 nm, were produced for further evaluation. The optimized formulations were characterized and showed a particle size in agreement to the predicted value, i.e. 33.6 nm and 74.6 nm, respectively. The optimized formulations were also characterized using multiple techniques in order to investigate the solid state of drug and excipients (DSC and XRD), particle morphology (TEM) and interactions between the formulation components (FTIR). Furthermore, particle size and surface charge of the formulations was studied during a one-month stability study and did not evidence any significative modification during storage.

Hierarchical micro-/mesoporous graphitic carbon spheres (HGCS) with a uniform diameter of ~0.35 μm were synthesized by Fe-catalyzed graphitization of amorphous carbon spheres resultant from hydrothermal carbonization. The HGCS resultant from 3 h at 900 °C with 1.0 wt% Fe catalyst had high graphitization degree and surface area as high as 564 m²/g. They also exhibited high specific capacitance of 140 F/g at 0.2 A/g, good electrochemical stability with 94% capacitance retention after consecutive 2500 cycles. The graphitization degree of the HGCS contributed about 60% of their specific capacitance, and their specific capacitance per unit surface area was as high as 0.2 F/m² which was much higher than in the most cases of porous amorphous carbon materials reported before. In addition, the HGCS showed a high adsorption capacity of 182.8 mg/g for methylene blue (MB), which was 12 times as high as that in the case of carbon spheres before graphitization.

A focal plane array (FPA) detector was used for hyperspectral imaging in the infrared (IR) spectral region using thermal and synchrotron light sources. FPA Fourier-transform IR (FTIR) imaging microspectroscopy will be able to monitor real time changes at specific absorption bands when combined with high brightness synchrotron source. In this study, several types of samples with unique structural motifs were selected and used for assessing the capability of the FPA-FTIR imaging technique. It was shown that the time required for polariscopy at IR wavelengths can be substantially reduced by the FPA-FTIR imaging approach. By using natural and laser fabricated polymers with sub-wavelength features, alignment of absorbing molecular dipoles was revealed as well as higher order patterns (laser fabricated structures). Micro-spectroscopy of absorber orientation reveals alignment patterns even when they are not spatially resolved.

Fullerene molecules are composed of carbon in forms of a hollow sphere, ellipsoid, or tube. Fullerenes have attracted considerable attention in different fields of science since their discovery in 1985. The unique carbon cage structure of fullerene provides immense scope for derivatization, rendering potential for various industrial applications. The prospective applications of fullerenes thus have led to assorted fullerene derivatives. The unique chemical structure also provides ease for fullerene to be synthesized through various kinds of conjugating techniques, where fullerene can be located either on the backbone or the branch chain. Here in this review, we have compiled the toxicity and biosafety aspects of fullerene in aquatic organisms. The frequent use of fullerene is likely to come in contact and interact with the aquatic environment and aquatic organisms. According to the current understanding, waterborne exposure to fullerene-based nanomaterials indeed triggers toxicities at cellular, organic, molecular as well as neurobehavioral levels.

Hydrogenated small fullerenes (Cn, n<60) are of interest as potential astrochemical species, and as intermediates in hydrogen catalysed fullerene growth. However computational identification of key stable species is difficult due to the vast combinatorial space of structures. In this study we explore routes to predict stable hydrogenated small fullerenes. We show that neither local fullerene geometry nor local electronic structure analysis are able to correctly predict subsequent low energy hydrogenation sites, and indeed sequential stable addition searches also sometimes fail to identify most stable hydrogenated fullerene isomers. Of the empirical and semi-empirical methods tested, GFN2-xTB consistently gives highly accurate energy correlation (r>0.99) to full DFT-LDA calculations at a fraction of the computational cost. This allows identification of the most stable hydrogenated fullerenes up to 4H for four fullerenes, namely two isomers of C28 and C40, via “brute force” systematic testing of all symmetry inequivalent combinations. The approach shows promise for wider systematic studies of smaller hydrogenated fullerenes.

Flexible and stretchable conductive materials have received significant attention in several applications such as flexible displays and sensors. In this paper, we report a highly dispersed porous Ag nanoflakes with clean surfaces were fabricated through an explosive growth process. The evolution process from silver nanoflakes to nanomeshes occurred by the novel “dissolution–recrystallization” solvothermal process. The as-obtained Ag meshes have the dual nature of nanoflakes and nanoparticles, which could create an intercross and interpenetration conductive network structures between silver and polymer in the printed elastic conductor, therefore, the silver meshes as conductive fillers used in elastic conductor simultaneously exhibit high conductivity and mechanical durability.

A nanostructured electrochemical bi-sensor system for analysis of milks has been developed using the Layer by Layer technique. The non-enzymatic sensor [CHI+IL/CuPcS]2, is a layered material containing a negative film of the anionic sulfonated copper phthalocyanine (CuPcS) acting as electrocatalytic material, and a cationic layer containing a mixture of an ionic liquid (IL) (1-butyl-3-methylimidazolium tetrafluoroborate) that enhances the conductivity and chitosan (CHI) that facilitates the enzyme immobilization. The biosensor ([CHI+IL/CuPcS]2-GAO) results from the immobilization of galactose oxidase on the top of the LbL layers. FTIR, UV-vis and AFM have confirmed the proposed structure and cyclic voltammetry has demonstrated the amplification caused by the combination of materials in the film. Sensors have been combined to form an electronic tongue for milk analysis. Principal Component Analysis has revealed the ability of the sensor system to discriminate between milk samples with different lactose content. Using PLS-1 calibration models, correlations have been found between the voltammetric signals and chemical parameters measured by classical methods. PLS-1 models provide excellent correlations with lactose content. Additional information about other components such as fats, proteins and acidity can also be obtained. The method developed is simple and the short response time permits its use in assaying milk samples on-line.

We propose a concept of hybrid nanoelectronic-magnetic device for logic integrated platforms made of magnetic core-shell nanoparticles deposited onto prepatterned Si (111) substrate with basic logic circuitry made of metallic conductive lines. The synthesis of magnetic material and the creation of nanoelectronic prepatterned interdigitated die is reported and its capabilities are demonstrated in terms of magnetotransport properties. The laser pyrolysis method is employed in order to synthesize magnetic core-shell Fe / FeC nanoparticles with sizes between 12 – 15 nm. E-beam lithography has been used in order to design and execute two different layouts of interdigitated die, prepatterned with logic capacity, one with two pads and 50 microns thick conductive metallic lines, another one with 4 pads and parallel 5 microns thick conductive lines separated by 5 microns thick spacer. The as-obtained structures are morphologically characterized by means of optical, scanning and transmission electron microscopies. As-synthesized core-shell nanoparticles have been magnetically characterized inasmuch as the hybrid device obtained by depositing centrifugated and dispersed core-shell nanoparticles from liquid carrier solutions. For the first time, a significant giant magnetoresistive (GMR) effect has been observed and measured for the hybrid architectured device made of Fe / FeC nanosized materials on pre-patterned interdigitated die. A ∆R/R of 8% at 4.2 K has been measured from conductivity-in-plane electron transport measurements. This opens possibilities for the use of such devices as arrays of nanosensors and in spintronic applications.

Principle of memristor presented by Leon Chua and time reversal based non-linear elastic wave spectroscopy (TR-NEWS) which can be applied to acoustic tomography are reviewed. Correlation of acoustic or electromagnetic nonlinear waves and its time reversed wave can produce strong signal. Materials like transducer or biological skin can be assumed to be composed of a large number of small elastic unit: hysteretic elementary unit (HEU), and one can take a HEU as a memristor whose operation depends on time. Relation between TR-NEWS and solitonic wave in fluid, and relation between decomposition of time reversal operator (DORT) and chaotic oscillation are discussed.

Controlling functional properties of matter and combine them for engineering a functional device is nowadays a common direction of scientific community. For instance, heterogeneous magnetic nanostructures can make use of different types of geometrical and compositional modulations to achieve the control of the magnetization reversal along with the nano-entities and thus enabling the fabrication of spintronic, magnetic data storage and sensing devices, among others. In this work, diameter modulated FeNi nanowires are fabricated paying special effort to obtain sharp transition regions between two segments of different diameters (from about 450 nm to 120 nm), enabling precise control over the magnetic behavior of the sample. Micromagnetic simulations performed on single bi-segmented nanowires predict a double step magnetization reversal where the wide segment magnetization switches near 200 Oe through a vortex domain wall, while at 500 Oe the magnetization of the narrow one is reversed through a corkscrew like mechanism. Finally, these results are confirmed with magneto-optic Kerr effect measurements at the transition of isolated bi-segmented nanowires. Furthermore, macroscopic vibrating sample magnetometry is used to demonstrate that the magnetic decoupling of nanowire segments is the main phenomenon occurring over the entire fabricated nanowires.

Carbon nanotubes are hybridized with metal crystals to impart multifunctionality into the nanohybrids (NHs). Simple but effective synthesis techniques are desired to form both zero-valent and oxides of different metal species on carbon nanotube surfaces. Sol-gel technique brings in significant advantages and is a viable technique for such synthesis. This study probes the efficacy of sol-gel process and aims to identify underlying mechanisms of crystal formation. Standard electron potential (SEP) is used as a guiding parameter to choose the metal species; i.e., highly negative SEP (e.g., Zn) with oxide crystal tendency, highly positive SEP (e.g., Ag) with zero-valent crystal-tendency, and intermediate range SEP (e.g., Cu) to probe the oxidation tendency in crystal formation are chosen. Transmission electron microscopy and X-ray diffraction are used to evaluate the synthesized NHs. Results indicate that SEP can be a reliable guide for the resulting crystalline phase of a certain metal species, particularly when the magnitude of this parameter is relatively high. However, for intermediate range SEP-metals, mix phase crystals can be expected. For example, Cu will form Cu₂O and zero-valent Cu crystals, unless the synthesis is performed in a reducing environment.

The adsorption of carbon dioxide on amino silanes-functionalized MCM-41 and SBA-15 materials is reported. The functionalization of mesoporous silicas was made by post-synthesis method, by impregnation of 3-aminopropyltriethoxysilane. The obtained materials were characterized by X-ray diffraction, scanning and transmission electron microscopies, nitrogen adsorption-desorption and X-ray photoelectron spectroscopy measurements. The carbon dioxide adsorption capacities for the samples were carried out under ambient pressures. The obtained results evidenced that amino-silanes with a terminal amine (–NH₂) were functionalized through covalent coupling of this group on the surface of the channels in the ordered mesoporous silica, meaning that the amine is anchored on the surface of the bigger pores of the MCM-41 and SBA-15 support. For functionalized materials, the CO₂ adsorption capacity of the AMCM-41 increased from 0.18 to 1.1 mmol·g⁻¹, whereas for ASBA-15, it was from 0.6 to 1.8 mmol·g⁻¹. The Lagergren kinetic algorithms were applied in order to validate the obtained results, evidencing the enhanced carbon dioxide adsorption capacity and stability of the functionalized ordered mesoporous molecular sieves.

This review focus on a critical analysis of nanocatalysts for Advanced Reductive Processes (ARP) and Oxidation Processes (AOP) designed for the degradation of poly/perfluoroalkyl substances (PFAS) in water. Ozone, ultraviolet and photocatalyzed ARP and/or AOP will be the basic treatment technologies. Besides the review of the nanomaterials with greater potential as catalyst for advanced processes of PFAS in water, the perspectives for its future development considering sustainability considerations will be discussed. Moreover, a brief analysis of the current state of the art of the ARP and AOP for the treatment of PFAS in water will be presented.

We report the electronic, magnetic and transport properties of a prototypical antiferromagnetic (AFM) spintronic device. We chose Cr as the active layer because it is the only room-temperature AFM elemental metal. We sandwiched Cr between two non-magnetic metals (Pt or Au) with large spin-orbit coupling. We also inserted a buffer layer of insulating MgO to mimic the structure and finite resistivity of a real device. We found that, while spin-orbit has a negligible effect on the current flowing through the device, the MgO layer plays a crucial role. Its effect is to decouple the Cr magnetic moment from Pt (or Au) and to develop an overall spin magnetization. We have also calculated the spin-polarized ballistic conductance of the device within the Büttiker-Landauer framework, and we have found that for small applied bias our Pt/Cr/MgO/Pt device presents a spin polarization of the current amounting to ~25%.

Conventional radiation therapy uses white X-rays that consist of a mixture of X-ray waves with various energy levels. In contrast, a monochromatic X-ray (monoenergetic X-ray) has a single energy level. Irradiation of high Z elements with a synchrotron generated monochromatic X-ray with the energy at or higher than the K-edge energy of the element results in the production of the Auger electrons that cause DNA damage leading to cell killing. Delivery of high Z elements into cancer cells and tumor mass can be facilitated by the use of nanoparticles. Mesoporous silica nanoparticles (MSNs) have been shown to be effective in delivering high Z elements to cancer cells. A proof of principle experiment was reported that demonstrated the feasibility of this approach. This opens up a possibility to pursue the Auger cancer therapy by the combined use of MSNs loaded with high Z elements and monochromatic X-rays. Similar cancer therapies using other types of quantum beams such as neutron, proton and carbon ion beams can be envisioned.

In the present study, we have followed the hydrothermal path for the synthesis of gold nanoparticles (Au NPs) from the biomaterial Elaeocarpus ganitrus seeds extract, which is a rapid, eco-friendly, non-chemical way. The prepared NPs were thoroughly analyzed by PXRD & HR-TEM studies and also tested for photocatalytic dye degradation and anticancer studies. Besides, antioxidant, antibacterial and anticancer properties of Au NPs were studied. In vitro studies revealed the dose-dependent cytotoxic effect of Au NPs. The prepared nanoparticles showed good cytotoxic impact against Prostate cancer (PC-3) cells line. The results of the present study could contribute to synthesize new and cost-effective drugs from Elaeocarpus ganitrus seeds extract by using bio approach.

Iron Doped TiO₂ nanoparticles (Fe-TiO₂) were synthesized and photocatalitically investigated under high and low fluence values of UV-radiation. The Fe-TiO₂ physical characterization was performed using X-ray Powder Diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area analysis, Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Diffuse Reflectance Spectroscopy (DRS), and X-Ray Photoelectron Spectroscopy (XPS) technique. The XPS evidenced that ferric ion (Fe³⁺) was in the lattice of TiO₂ and co-dopants no intentionally added were also present due to the precursors of the synthetic method. The Fe³⁺ concentration played a key role in the photocatalytic generation of hydroxyl radical (•OH) and estriol (E3) degradation. Fe-TiO₂ materials accomplished E3 degradation, and it was found that the catalyst with 0.3 at. % content of Fe (0.3 Fe-TiO₂) enhanced the photocatalytic activity under low UV-irradiation compared with no intentionally Fe-added TiO₂ (zero-iron TiO₂) and Aeroxide^® TiO₂ P25. Furthermore, the enhanced photocatalytic activity of 0.3 Fe-TiO₂ under low UV-irradiation may have applications when radiation intensity must be controlled, as in medical applications, or when strong UV absorbing species are present in water.

Volatile organic compounds (VOCs) are among the most abundant air pollutants. Their high concentrations can adversely affect the human body and therefore, early detection of VOCs is of outmost importance. Among the different VOCs, in this review paper, we have focused our attention on the monitoring of acetaldehyde by chemiresistive gas sensors using nanostructured semiconducting metal oxides. These sensors not only can provide a high sensing signal for detection of acetaldehyde, but also high thermal and mechanical stability and low price. This review paper is divided into three major sections. First, we will introduce acetaldehyde as the target gas and the importance of its detection. Then, the fundamentals of chemiresistive gas sensors will be briefly presented and, in the last section, a survey of literature on acetaldehyde gas sensors will be discussed. Acetaldehyde sensors working mechanism, their structures and configurations are reviewed. Finally, the future development outlook and potential applications are discussed, giving a complete panoramic view for researcher working and interested in acetaldehyde detection for different purposes in many fundamentals and applicative fields.

A theoretical nonlocal thermoelastic model for studying the effects of the thermal conductivity variability on a rotating nanobeam has been described in the present article. The theory of thermal stress is employed using the Euler–Bernoulli beam model and generalized heat conduction with phase lags. It is believed that the thermal conductivity of the current model varies linearly according to temperature. Due to variable harmonic heat, the considered nanobeam excited and was subjected to a time-varying exponential decay load. Using the Laplace transform process, the analytical solutions for displacement, deflection, thermodynamic temperature and bending moment of rotating nanobeams are provided in final forms and a numerical example has been taken to address the problem. A comparison of the stated results was displayed and additionally, the influences of non-local parameters and varying load were analyzed and examined. We also investigate how the linear changes in the temperature of physical properties can influence both the static and dynamic responses to the rotating nanobeam.

Binderless zeolite macrostructures in the form of ZK-4 microspheres were prepared using anion exchange resin beads as shape directing macrotemplates. The particles were synthesized under hydrothermal conditions at different temperatures and treatment times. The influence of the different synthesis parameters was investigated by X-ray diffraction, scanning electron microscopy, fluorescence X, nitrogen adsorption measurements and ²⁹Si solid NMR. Fully crystalline spheres similar in size and shape to the original resin beads were obtained by a hydrothermal treatment at the highest temperatures (150 - 180 °C) for a short treatment time of 24 h. The synthesized microspheres showed to be promising in the molecular decontamination of Volatile Organic Compounds (VOCs).

Methylsilsesquioxane aerogels with uniform mesopores have been facilely prepared via a sol–gel process followed by microwave drying with methyltrimethoxysilane (MTMS) as precursor, hydrochloric acid (HCl) as catalyst, water and methanol as solvents, hexadecyltrimethylammonium chloride (CTAC) as surfactant and template and propylene oxide (PO) as gelation agent. The microstructure, chemical composition and pore structures of the resultant MSQ aerogels were investigated in detail to achieve controllable preparation of MSQ aerogels, and the thermal stability of MSQ aerogels was also analyzed. The gelation agent, catalyst, solvent and microwave power have important roles on pore structures of MSQ aerogels. Meanwhile, microwave drying method is found to not only have a remarkable effect on improving production efficiency, but also be conducive to avoid the collapse of pore structure especially micropores during drying. The resulting MSQ aerogel microwave-dried at 500 W possesses a specific surface area up to 821 m2/g and a mesopore size of 20 nm, and displays good thermal stability.

In two-dimensional materials research, oxidation is usually considered as a common source for the degradation of electronic and optoelectronic devices or even device failure. However, in some cases a controlled oxidation can open the possibility to widely tune the band structure of 2D materials. In particular, we demonstrate the controlled oxidation of titanium trisulfide (TiS₃), a layered semiconductor that attracted much attention recently thanks to its quasi-1D electronic and optoelectronic properties and its direct bandgap of 1.1 eV. Heating TiS₃ in air above 300 °C gradually converts it into TiO₂, a semiconductor with a wide bandgap of 3.2 eV with applications in photo-electrochemistry and catalysis. In this work, we investigate the controlled thermal oxidation of individual TiS₃ nanoribbons and its influence on the optoelectronic properties of TiS₃-based photodetectors. We observe a step-wise change in the cut-off wavelength from its pristine value ~1000 nm to 450 nm after subjecting the TiS₃ devices to subsequent thermal treatment cycles. Ab-initio and many-body calculations confirm an increase of the bandgap of titanium oxysulfide (TiO_2-xS_x) when increasing the amount of oxygen and reducing the amount of sulfur.

Hematite (-Fe2O3) with uniform hexagonal flakes morphology has been successfully synthesized using a combination of gelatin as natural template with F127 via hydrothermal method. The resulting hematite was investigated as adsorbent and photocatalyst for removal of ibuprofen as pharmaceutical waste. Hexagonal flake-like hematite was obtained following calcination at 500 oC with the average size was measured at 1-3 µm. Increasing the calcination temperature to 700 oC transformed the uniform hexagonal structure into cubic shape morphology. Hematite also showed high thermal stability with increasing the calcination temperatures, however, the surface area was reduced from 47 m2/g to 9 m2/g. FTIR analysis further confirmed the formation Fe-O-Fe bonds, and the main constituent elements of Fe and O were observed in EDX analysis for all samples. Fe2O3-G samples have an average adsorption capacity of 55-25.5 mg/g at 12-22% of removal efficiency when used as adsorbent for ibuprofen. The adsorption capacity was reduced with increasing the calcination temperatures due to the reduction of available surface area of the hexagonal flakes when transformed into cube. Photocatalytic degradation of ibuprofen using hematite flakes achieved 50% of removal efficiency meanwhile combination of adsorption and photocatalytic degradation further removed 80% of ibuprofen in water/hexane mixtures.

Based on the principle of Pancharatnam-Berry phase, we propose an approach to construct dual-functional dielectric metasurface doublets. This type of doublet, which is composed of a substrate and two metasurface layers, performs two different functionalities at two different operating wavelengths. The simulated results of the examples show that the designed dual-functional doublet works well as expected. The proposed approach can be used to design dielectric meta-structures with more layers of meta-surface and thereby with more functionalities, and would be of interest for miniaturization and integration.

Hybrid lead halide perovskites have been revolutionary in the photovoltaic research field, reaching efficiencies comparable with the most established photovoltaic technologies, although they do not yet reach their competitor stability. The search for a stable configuration required the engineering of the charge extraction layers; in this work, molecular doping is used as an efficient method for small molecule and polymer, employed as hole transport materials in planar heterojunction configuration on compact-TiO2. We proved the viability of this approach, obtaining significantly increased performances and reduced hysteresis on compact titania-based devices. We investigated the photovoltaic performance, correlating to the hole transport material structure. We have demonstrated that the molecular doping mechanism is more reliable than the oxidative doping, and verified that molecular doping in polymeric hole transport materials leads to highly efficient perovskite solar cell, with long-term stability.

Controlling surface-protein interaction during wastewater treatment is the key motivation for developing functionally modified membranes. A new biocatalytic thermo-responsive poly(vinylidene fluoride)(PVDF)/nylon-6,6/poly(N-isopropylacrylamide)(PNIPAAm) ultrafiltration membrane was fabricated to achieve dual functionality of protein-digestion and thermo-responsive self-cleaning. The PVDF/nylon-6,6/PNIPAAm composite membranes were constructed by integrating a hydrophobic PVDF cast layer and hydrophilic nylon-6,6/PNIPAAm nanofiber layer where trypsin enzymes were covalently immobilized. The immobilization density of enzymes on the membrane surface decreased with increasing PNIPAAm concentration, due to the decreased number of amine functional sites. Through a ultrafiltration study using a model solution containing BSA/NaCl/CaCl₂, the PNIPAAm containing biocatalytic membranes demonstrated a combined effect of enzymatic and thermo-switchable self-cleaning. The membrane without PNIPAAm revealed superior fouling resistance and self-cleaning with an R_PD of 22%, compared to membranes with 2 and 4 wt% PNIPAAm with 26% and 33% R_PD, respectively, after an intermediate temperature cleaning at 50°C, indicating that higher enzyme density offers more efficient self-cleaning than the combined effect of enzyme and PNIPAAm at low concentration. The conformational volume phase transition of PNIPAAm did not affect the stability of immobilized trypsin on membrane surface. Such novel surface engineering design offer a promising route to severe surface-protein contamination remediation in food and wastewater applications.

For development and successful application of any material, a clear understanding of their mechanical behavior is one of the most important things, but when it comes to nanofibers networks it become a challenge due to, their high porosity, many scales in their structure, and characteristics non-linear. Therefore, an experimental methodology in conjunction with a theoretical model that can fully consider their characteristics is still needed. In this work we proposed a model that incorporates the propagation of the elastic waves in two-phase media to determine the effective elastic modulus of electrospun membranes of PLA/gelatin given the mechanical properties of nanofibers, shape, distribution and concentration. The model was verified via laser ultrasonic testing. It was found that the values predicted for the effective modulus by the model were higher than the values obtained from experimental results. One explanation is due to the experimental density. As a result, the P-Wave velocity from the model best fit to experimental results and it has the same behavior, decrees as the concentration of gelatin in the solution. These results indicate the model and experimental methodology can assist in the dressing of nanofibers networks and electrospun materials.

The use of nanomaterials has been increasing in recent times, and they are widely used in industries such as cosmetics, drug, food, water treatment and agriculture. The rapid development of new nanomaterials demands a set of approaches to evaluate the potential toxicity and risks related to them. In this regard, nanosafety has been using and adapting already existing methods (toxicological approach), but the unique characteristics of nanomaterials demand new approaches (nanotoxicology) to fully understand the potential toxicity, immunotoxicity and (epi)genotoxicity. Also, new technologies, such as organ-on-chip and sophisticated sensors, are under development and/or adaptation. All the information generated is used to develop new in silico approaches trying to predict the potential effects of newly developed materials. The overall evaluation of how from the production to final disposition chain of nanomaterials is evaluated under Life Cycle Assessment (LCA), which is becoming an important element of nanosafety considering sustainability and environmental impact. In this review we give an overview of all these elements of nanosafety.

Cadmium telluride (CdTe), a metallic dichalcogenide material, has been utilized as an absorber layer for thin film-based solar cells with appropriate configurations, and the SCAPS-1D structures program has been used to evaluate the results. In both known and developing thin film photovoltaic systems, a CdS thin film buffer layer has been frequently employed as a traditional n-type heterojunction partner. In this study, numerical simulation was used to find a suitable non-toxic material for the buffer layer instead of CdS, among various types of buffer layers (ZnSe, ZnO, ZnS, and In2S3), and carrier concentrations for the absorber layer (NA) and buffer layer (ND) were varied to determine the optimal simulation parameters. carrier concentrations (NA from 2 x 1012 cm-3 to 2 x 1017 cm-3 and ND from 1 x 1016 cm-3 to 1 x 1022 ??−3) have been differed. The results showed that the CdS as buffer layer based CdTe absorber layer solar cell has the highest efficiency (?%) of 17.43%. Furthermore, high conversion efficiencies of 17.42% and 16.27% have been found for ZnSe and ZnO based buffer layers, respectively. As a result, ZnO and ZnSe are potential candidates for replacing the CdS buffer layer in thin-film solar cells. Here, the absorber (CdTe) and buffer (ZnSe) layers were chosen to improve the efficiency by finding the optimal density of the carrier concentration (acceptor and donor). The simulation findings above provide helpful recommendations for fabricating high-efficiency metal oxide-based solar cells in the lab.

High degree of polymerisation agave fructans (HDPAF) are presented as a novel encapsulating material. Electrospraying coating (EC) was selected as the encapsulation technique and β-carotene as the model bioactive compound. In case of direct electrospraying, two encapsulation methodologies (solution and emulsion) were proposed to find the formulation which provided a suitable particle morphology and an adequate concentration of β-carotene encapsulated in the particles. SEM images showed spherical particles with sizes ranging from 440 to 880 nm depending on the concentration of HDPAF and processing parameters. FTIR analysis confirmed interaction and encapsulation of β-carotene with HDPAF. Thermal stability of β-carotene encapsulated in HDPAF was evidenced by thermogravimetric analysis (TGA). The study showed that β-carotene encapsulated in HDPAF by the EC method remained stable for up to 50 h of exposure to UV light. Therefore, HDPAF is a viable option to formulate nanocapsules as a new encapsulating material. In addition, EC allowed increasing the ratio β-carotene:polymer as well as its photostability.

Due to the rapid development of nanotechnologies, materials, in particular , solid dispersions (SDs), which are actively introduced into the life of modern man, have been obtained. Special progress in this area is observed in industry and medicine. The use of SDs in agriculture is lagging far behind, despite the growing number of scientific papers on this topic. At the same time, the prospects for the introduction of SDs in the agro-industrial complex are obvious. The review presents the results of research on the development of innovative preparations based on SD to protect plants from diseases and pests of cultivated plants, as well as parasiticides to protect animal health based on modern achievements of nanotechnology. One of these technologies is the methods of mechanochemistry, which improve the properties of poorly soluble biologically active substances by their joint mechanical treatment with water-soluble polymers and auxiliary substances.

Hybrid metal-halide perovskites have emerged as leading class of semiconductors for photovoltaic devices with remarkable light harvesting efficiencies. The formation of methylammonium lead iodide (CH₃NH₃PbI₃) perovskite into mesoporous titania (TiO₂) scaffold by a sequential deposition technique is known to offer better control over the perovskite morphology. The growth reactions at the mesoporous TiO₂ film depend on reactants concentration in the host matrix and the reaction activation energy. Here, we are characterizing formation of CH₃NH₃PbI₃ perovskite in mimic solar cell photoelectrodes utilizing the developed NanoPlasmonic Sensing (NPS) approach. Based on dielectric changes at the TiO₂ mesoporous film interface, the technique provides time-resolved spectral shifts of the localized surface plasmon resonance that varies widely depending on the different operating temperatures and methylammonium iodide (CH₃NH₃I) concentrations. Analytical studies included Ellipsometry, Scanning Electron Microscopy, and X-ray diffraction. The results show that perovskite conversion can be obtained at lower CH₃NH₃I concentrations if reaction activation energy is lowered. A significant finding is that the NPS response at 350 nm mesoporous TiO₂ can widely change from red shifts to blue shifts depending on extent of conversion and morphology of perovskite formed at given reaction conditions.

Though the energy density of lithium-ion batteries continues to increase, safety issues related with the internal short-circuit and the resulting combustion of highly flammable electrolyte impede the further development of lithium-ion batteries. It has been well-accepted that a thermal stable separator is important to postpone the entire battery short-circuit and thermal-runaway. Traditional methods to improve the thermal stability of separators includes surface modification and/or developing alternate material systems for separators which may always affect the battery performance negatively. Herein, a thermostable and shrink-free separator with little compromise in battery performance is prepared by coaxial electrospinning and tested. The separator consists of core-shell fiber networks where poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) layer serves as shell and polyacrylonitrile (PAN) as the core. This core-shell fiber network exhibits little or even no shrinking/melting at elevated temperature over 250 °C. Meanwhile, it shows excellent electrolyte wettability and can take large amount of liquid electrolyte three times more than that of conventional Celgard 2400 separator. In addition, the half-cell using LiNi1/3Co1/3Mn1/3O2 as cathode and the aforementioned electrospun core-shell fiber network as separator demonstrates superior electrochemical behavior, stably cycling for 200 cycles at 1 C with a reversible capacity of 130 mAh g-1 and little capacity decay.

In the preparation of polymer-clay nanocomposites the chemical incompatibility between the clay surface and polyolefins can be overcome by using clays organically modified with short chain organic cations. The compatibility can be further enhanced by using functionalized polymer that wets the clay surface while being miscible with the non-polar polymer matrix. In this work we tried to modify the host polymer polypropylene (PP) by irradiating it with gamma-rays in air knowing that it undergoes oxidation and chain scission simultaneously. Thus lower molecular weight PP with highly polar surface due to oxidation can be expected to play double role of clay modifier and functional compatibilizer. This has been observed to be the case. Finely ground PP granules were irradiated in air in a ⁶⁰Co γ-irradiator at the dose rate of 0.08 kGy/h (low dose rate to enhance oxidation) to 5, 10, and 20 kGy total doses. The extent of oxidation and change in molecular weight were determined by ATR-FTIR and Melt Flow Rate measurements respectively. PP/MMT nanocomposites were prepared by using 20% γ-PP, 1-5 % MMT and pristine PP to make up the total 100 in a torque rheometer. Maleated PP was also used in similar quantities to compare the effectiveness of γ-PP as a compatibilizing agent. Nanocomposites prepared with 10 kGy irradiated PP was found to show optimum mechanical properties among all formulations, with 26% increase in E-modulus and 10% increase in tensile strength as compared to pristine PP. Ternary PP nanocomposites were characterized by XRD, SAXS and PALS studies.

The development of organic devices has been focused in their miniaturization in order to obtain denser and faster electronic circuits. The challenge is to build the devices adding atom by atom or molecule by molecule until the desired structure is achieved. To do this job, techniques able to see and manipulate matter at this scale are needed. Scanning tunneling microscopy has been the selected technique by scientists to develop smart and functional unimolecular devices. This review article compiles the latest developments in this field giving examples of supramolecular systems monitored and fabricated at molecular scale by bottom-up approaches using STM at solid/liquid interface.

Hemoconcentration membranes used in cardiopulmonary bypass require a pore structure design with high pure water permeability, and which does not allow protein adsorption and useful protein loss. However, studies on hemoconcentration membranes have not been conducted yet. The purpose of this study was to analyze three-dimensional pore structures and protein fouling before and after blood contact with capillary membranes using the tortuous pore diffusion model and a scanning probe microscope system. We examined two commercially available capillary membranes of similar polymer composition that are successfully used in hemoconcentration clinically. Assuming the conditions of actual use in cardiopulmonary bypass, we perfused these membranes with bovine blood. Pure water permeability before and after bovine blood perfusion was measured using the dead-end filtration. The scanning probe microscopy system was used for analysis. High-resolution three-dimensional pore structures on the inner surface of the membranes were observed before blood contact. On the other hand, pore structures after blood contact could not be observed due to protein fouling. The pore diameters calculated by the tortuous pore diffusion model and scanning probe microscopy were mostly similar and could be validated reciprocally. Achievable pure water permeabilities showed no difference despite protein fouling, leading to low values of albumin SC. This is due to the mechanism that protein fouling occurs on the membrane surface, while there is little internal pore blocking. Therefore, controlling the fouling is essential for membranes in medical use. These characteristics of the hemoconcentration membranes examined in this study are suitable for clinical use.

Liposomes have been used for several decades for the encapsulation of drugs and bioactives in cosmetics and cosmeceuticals. On the other hand, the use of these phospholipid vesicles in food applications is more recent and has been increasing significantly in the last ten years. Although in different stages of technological maturity - in the case of cosmetics, many products are on the market - processes to obtain liposomes suitable for the encapsulation and delivery of bioactives are highly expensive, especially aiming at scaling-up. Among the bioactives proposed for cosmetics and food applications, vitamins are the most frequently used. Despite the differences between the administration routes (oral for food and mainly dermal for cosmetics), some challenges are very similar (e.g., stability, bioactive load, average size, increase of drug bioaccessibility and bioavailability). In the present work, a systematic review of the technological advancements in the nanoencapsulation of vitamins using liposomes and related processes was performed; challenges and future perspectives were also discussed in order to underline the advantages of these drug loaded biocompatible nanocarriers for cosmetics and food applications.

Various efforts have been made to detect minimum value of glucose in any medium like water or body buffer solutions with high-sensitivity, accurate, and low-cost sensors in order to enhance life style. Therefore, the present study was done to investigate reliability of two-dimensional plasmonic structure by circular dichroism (CD) and ellipsometry tools in different concentrations of glucose. Our results confirmed a dependency of the CD signal on glucose concentrations and also a very good sensitivity based on the phase difference between each polarization in ellipsometry parameters with the help of an achiral plasmonic structure.

Surface passivation, which has been intensively studied recently, is essential for the perovskite solar cells (PSCs), due to the intrinsic defects in perovskite crystal. A series of chemical or physical methods have been published for passivating the defects of perovskite, which effectively suppressed the charge recombination and enhanced the photovoltaic performance. In this study, the n-type semiconductor of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) is dissolved in chlorobenzene (CB) for the surface passivation during the spin-coating process for depositing the two-dimensional (2D) perovskite film. This approach simplifies the fabrication process of 2D PSCs and benefits the film quality. As a result, the defects of perovskite film are effectively passivated by this method. A better perovskite/PCBM heterojunction is generated, exhibiting an increased film coverage and improved film morphology of PCBM. It is found that this technology results in an improved electron transporting performance as well as suppressed charge recombination for electron transport layer. As a result, PSCs based on the one-step formed perovskite/PCBM heterojunctions exhibit the optimized power conversion efficiency of 15.69% which is about 37% higher than that of regular perovskite devices. The device environmental stability is also enhanced due to the quality-improved electron transport layer.

Understanding potential uptake and biodistribution of engineered nanoparticles in soil-grown plants is imperative for toxicity and risk assessment considering the oral exposure of edibles by humans. Herein, we assessed potential influence of particle size (25, 50, and 250 nm) and concentration (0, 50, 100, 200, and 500 mg/kg-soil) of Copper oxide nanoparticles (CuONPs) on: (1) the root system architecture, and the physicochemical attributes of soil at the soil-root interface, (2) leading to Cu transport and accumulation in root, stem, leaf and seed in soybean (Glycine max cv Kowsar) grown for entire lifecycle of 120 days, and compared with soluble Cu²⁺ ions and water-only controls, and (3) performed a comparative assessment of total seed Cu levels in soybean with other valuable food sources for Cu intake and discussed its human health implications. Our findings showed particle size- and concentration-dependent influence of CuONPs on Cu uptake and tissue distribution in root, stem, leaf and seed in soybean. Alterations in root architecture (root dry weight, root length, root volume, and root area) were dependent on the Cu compound type, Cu concentrations, and their interactions (p<0.05), except for root density. Concentration-response relationships for all three sized CuONPs, and Cu²⁺ ions, were linear. CuONPs and Cu²⁺ ions had inhibitory effects on root growth and development. Overall, soybean responses to smallest size CuONPs-25 nm were higher for all parameters investigated compared to two larger sized CuONPs (50 nm, 250 nm) or Cu²⁺ ions. Cu uptake/bioaccumulation differed among soybean tissues in the order: root > leaf > stem > seed. Despite reduced root architecture and seed yield, our smallest size CuONPs-25 nm led to increased total seed Cu uptake compared to the larger sized CuONPs and Cu²⁺ ions tested. Our findings also suggest that soil amendment by CuONPs, more so by the smallest size CuONPs-25 nm, could significantly improve nutritional Cu value in soybean seed as reflected by % Daily Values (DV), and are rated “Good” to “Very Good” according to the “World’s Healthiest Foods” rating. However, until the potential toxicity and risk from consumption of soybean seed is characterized in humans, caution should be exercised when the Cu fortified seeds are used for daily human consumption when addressing Cu deficiency and associated illnesses, globally.

Herein, we present a combination of experimental and computational study on the mitochondrial F0F1-ATPase nanotoxicity inhibition induced by single-walled carbon nanotubes (SWCNT-pristine, SWCNT-COOH). To this end, the in vitro inhibition responses in submitochondrial particles (SMP) as F0F1-ATPase enzyme were strongly dependent on the concentration assay (from 3 to 5 µg/ml) for both types of carbon nanotubes. Besides, both SWCNTs show an interaction inhibition pattern like the oligomycin A (the specific mitochondria F0F1-ATPase inhibitor). Furthermore, the best crystallography binding pose obtained for the docking complexes based on the free energy of binding (FEB), fit well with the previous in vitro evidences from the thermodynamics point of view. Following an affinity order as: FEB (oligomycin A/F0-ATPase complex) = -9.8 kcal/mol > FEB (SWCNT-COOH/F0-ATPase complex) = - 6.8 kcal/mol ~ FEB (SWCNT-pristine complex) = -5.9 kcal/mol. With predominance of van der Waals hydrophobic nanointeractions with key F0-ATPase binding site residues (Phe 55 and Phe 64). By the other hand, results on elastic network models, and fractal-surface analysis suggest that SWCNTs induce significant perturbations by triggering abnormal allosteric responses and signals propagation in the inter-residue network which could affect the substrate recognition ligand geometrical specificity of the F0F1-ATPase enzyme in order (SWCNT-pristine > SWCNT-COOH). Besides, the performed Nano-QSTR models for both SWCNTs show that this method may be used for the prediction of the nanotoxicity induced by SWCNT. Overall, the obtained results may open new avenues toward to the better understanding and prediction of new nanotoxicity mechanisms, rational drug-design based nanotechnology, and potential biomedical application in precision nanomedicine.

Currently, the use of sustainable chemistry as an ecological alternative for the generation of products or processes, free of polluting substance has assumed a preponderant role. The aim of this work is propose a bioinspired, facile, at low cost, non-toxic and environmentally friendly alternative to obtaining magnetic nanoparticles whit a majority phase of magnetite (Fe₃O₄). Is important to empathize that the synthesis was based on the chemical reduction through the Cnicus Benedictus extract, whose use as reducing agent has not been reported in the synthesis of iron oxides nanoparticles. In addition, the Cnicus Benedictus is abundant endemic plant in Mexico, with several medicinal properties and a large number of natural antioxidants. The obtained nanoparticles exhibited significant magnetic and antibacterial properties and an enhanced photocatalytic activity. The crystallite size of the Fe₃O₄ nanoparticles (Fe₃O₄ NP’s) was calculated by Williamson-Hall method. The photocatalytic properties of the Fe₃O₄ NP´s were studied by kinetics absorptions models in the Congo red (CR) degradation. Finally the antibacterial effect of the Fe3O4 NP´s were evaluated mediated the Kirby-Bauer method against E. coli and S. aureus bacteria. This route offers a green alternative to obtain Fe3O4 NP´s with remarkable magnetic, photocatalytic and antibacterial properties.

The harmful nature of high concentrations of antibiotics to humans and animals requires urgent development of novel materials and techniques for their absorption. In this work, CTAB (Cetyltrimethyl Ammonium Bromide)-assisted synthesis of ZIF-8 (zeolitic imidazolate framework) derived hollow carbon (ZHC) was designed, prepared and used as a high-performance adsorbent, further evaluated by Langmuir and Freundlich isothermal adsorption experiments, dynamic analysis as well as theoretical calculation. The maximum capacities of ZHC on adsorbing tetracycline (TC), norfloxacin (NFO) and levofloxacin (OFO) are 267.3, 125.6 and 227.8 mg g^-1, respectively, which delivers superior adsorptive performance when compared to widely studied inorganic adsorbates. The design concept of ZIFs-derived hollow carbon material provides guidance and insights for the efficient adsorbent of environmental antibiotics.

Programmed cell death protein 1 (PD-1) is a biomarker on the surface of cells that has a role in promoting self-tolerance by suppressing the inflammatory activity of T cells. In this work, one peptide of PD-1 was used as the template in molecular imprinting. The magnetic peptide-imprinted poly(ethylene-co-vinyl alcohol) composite nanoparticles (MPIP NPs) were characterized by dynamic light scattering (DLS), high-performance liquid chromatography (HPLC), Brunauer-Emmett-Teller (BET) analysis and superconducting quantum interference device (SQUID) analysis. Natural killer-92 (NK-92) cells were added to these composite nanoparticles and then incubated with human hepatoma (HepG2) cells. The viability and apoptosis pathway of HepG2 were then studied using cell counting kit-8 (CCK8) and the quantitative real-time polymerase chain reaction (qRT-PCR), respectively. These nanoparticles were found significantly enhance the activity of natural killer cells toward HepG2 cells by increasing expression of NK-kB, caspase 8 and especially caspase 3.

In this work, we investigated for the first time the complexation of sepiapterin (SP), the natural precursor of the natural essential cofactor tetrahydrobiopterin, that displays mild water-solubility and short biological half-life, with the hydrophobic triacetyl-β-cyclodextrin (TAβCD) to improve its encapsulation within methoxy-poly(ethylene-glycol)-poly(epsilon-caprolactone) (mPEG-PCL) nanoparticles. First, TAβCD-SP complexes were produced by spray-drying of TAβCD/SP binary solutions by utilizing the Nano Spray Dryer B-90 HP. Then, dry powders were characterized by differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR) and transmission and scanning electron microscopy (SEM and TEM, respectively) and compared to the complex components and physical mixtures (PMs). Next, SP was encapsulated within methoxy-poly(ethylene-glycol)-poly(epsilon-caprolactone) (mPEG-PCL) nanoparticles by nanoprecipitation of a SP/TAβCD complex/mPEG-PCL solution. In addition to complex nanoencapsulation, we assessed encapsulation of pure SP by nanoprecipitation with an intermediate step, which comprised the co-drying of SP, TAβCD and mPEG-PCL copolymer solution in organic solvent; this step aimed to promote the formation of molecular interactions between SP, TAβCD and the PCL blocks in the copolymer. SP-loaded mPEG-PCL nanoparticles were characterized by dynamic light scattering (DLS) and SEM. Nanoparticles with size of 74-75 nm and small polydispersity index (PDI <0.1) were obtained when SP-TAβCD equimolar spray-dried complex was used for nanoencapsulation, and SEM analysis indicated the absence of free SP crystals. Moreover, the encapsulation efficiency (%EE) and drug loading (DL) were 85% and 2.6%, respectively, as opposed to those achieved with pure SP encapsulation (14% and 0.6%, respectively). Overall, our results confirm that spray-drying of SP/TAβCD solutions at the appropriate molar ratio leads to the hydrophobization of the relatively hydrophilic SP molecule, enabling its encapsulation within mPEG-PCL nanoparticles.

We reveal the significance of plasmonic nanoparticle’s (NP) shape and its surface morphology en route to an efficient self-assembled plasmonic nanoparticle cluster. A simplified model is simulated in the form of free-space dimer and trimer nanostructures (NPs in shape of sphere, cube, and disk). A ~ 200 % to ~ 125% raise in near field strength (gap mode enhancement) is observed for spherical NPs in comparison with cubical NPs (from 2 nm to 8 nm gap sizes). Full-width three-quarter maximum reveals better broad-spectral optical performance in a range of ~ 100 nm (dimer) and ~ 170 nm (trimer) from spherical NPs as compared to a cube (~ 60 nm for dimer and trimer). These excellent properties for sphere-based nanostructures are merited from its dipole mode characteristics.

Today, more disciplines are intercepting each other, giving rise to “cross-disciplinary” research. Technological advancements in material science and device structure and production have paved the way towards development of new classes of multi-purpose sensory devices. Organic phototransistors (OPTs) are photo-activated sensors based on organic field-effect transistors that convert incident light signals into electrical signals. The organic semiconductor (OSC) layer and three-electrode structure of an OPT offer great advantages for light detection compared to conventional photodetectors and photodiodes, due to their signal amplification and noise reduction characteristics. Solution processing of the active layer enables mass production of OPT devices at significantly reduced cost. The chemical structure of OSCs can be modified accordingly to fulfil detection at various wavelengths for different purposes. Organic phototransistors have attracted substantial interest in a variety of fields, namely biomedical, medical diagnostics, healthcare, energy, security, and environmental monitoring. Lightweight and mechanically flexible and wearable OPTs are suitable alternatives not only at clinical levels but also for point-of-care and home-assisted usage. In this review, we aim to explain different types, working mechanism and figures of merit of organic phototransistors and highlight the recent advances from the literature on development and implementation of OPTs for a broad range of research and real-life applications.

The conventional rolled-up model for carbon nanocones assumes that the cone is constructed from a rolled-up graphene sheet joined seamlessly, which predicts five distinct vertex angles. This model completely ignores any effects due to the changing curvature and all bond lengths and bond angles are assumed to be those for the planar graphene sheet. Clearly curvature effects will become more important closest to the cone vertex, and especially so for the cones with the smaller apex angles. Here we construct carbon nanocones which in the assembled cone are assumed to comprise bond lengths and bond angles which are, as far as possible, equal throughout the structure at the same distance from the conical apex. Predicted bond angles and bond lengths are shown to agree well with those obtained by relaxing the conventional rolled-up model using the LAMMPS software. The major objective here is not simply to model physically realisable carbon nanocones for which numerical procedures are far superior, but rather to produce an improved model that takes into account curvature effects close to the vertex, and from which we may determine an analytical formula which represents an improvement on that for the conventional rolled-up model.

Non-enzymatic glucose sensing is a crucial field of study because of the current market demand. This study proposes a novel design of glucose sensor with enhanced selectivity and sensitivity by using graphene Schottky diodes, which is composed of Graphene/Platinum Oxide/n-Silicon heterostructure. The sensor was tested with different glucose concentrations and interfering solutions to investigate its sensitivity and selectivity. Different structures of the device were studied by adjusting the platinum oxide film thickness to investigate its catalytic activity. It was found that the film thickness plays a significant role in the efficiency of glucose oxidation and hence in overall device sensitivity. Moreover, theoretical investigations were conducted using Density Function Theory (DFT) to better understand the detection method and the origins of selectivity. The working principle of the sensors puts it in a competitive position with other non-enzymatic glucose sensors. DFT calculations provided a qualitative explanation of the charges distributed across the graphene sheet within a system of a platinum substrate with D-glucose molecules above. The proposed graphene/PtO/n-Si heterostructure has proven to satisfy these factors, which opens the door for further developments of more reliable non-enzymatic glucometers for continuous glucose monitoring systems.