Abstract: This study successfully developed a novel tumor-associated macrophages (TAMs)-targeting nanoplatform-sialic acid-disulfide bond-camptothecin (SA-SS-CPT) nanowires. This system significantly improved the solubility and bioavailability of camptothecin (CPT) and achieved active targeted drug delivery by utilizing sialic acid as a targeting ligand to specifically recognize the highly expressed Siglec-E receptor on TAMs. Upon internalization into TAMs, the disulfide bond in the SA-SS-CPT nanowires was cleaved in response to intracellular glutathione (GSH), leading to the controlled re-lease of CPT. SA-SS-CPT induced DNA damage in TAMs, thereby activating the cGAS-STING signaling pathway, promoting the polarization of TAMs toward the M1 phenotype, enhancing pro-inflammatory and anti-tumor immune responses, and effec-tively inhibiting tumor immune escape. Furthermore, the SA-SS-CPT nanowires syner-gistically enhanced the efficacy of PD-L1 blockade immunotherapy, collectively remod-eling the tumor immune microenvironment and ultimately facilitating significant tumor clearance.

Abstract: Hydrophobic carbon quantum dots (hbCQDs) with tunable photoluminescence were synthesized via a solvothermal approach and further hybridized with Rhodamine B (RhB) to extend emission into the visible range. The hbCQDs exhibit quasi-spherical morphology with an average particle size of 8 nm and predominantly disordered graphitic structure, as confirmed by TEM and XRD analyses. FTIR and XPS characterizations reveal surface functional groups including C–N, C=O/C–O, and S–H, which govern the photoluminescence properties. Pure hbCQDs display blue emission at 453 nm under excitation, with a quantum yield (QY) of 6.2%. Incorporation of RhB leads to dual-emission behavior: the surface-state emission remains in the blue region, while molecular-state emission from RhB appears in the orange-red region. The 0.2 mL RhB–CQD composite exhibits optimal properties, including a QY of 13% and a production yield of 82%, emitting white light under 365 nm UV excitation. Increasing RhB loading to 0.4 mL results in a shift of emission peaks and a reduced QY (<9%), with weaker orange fluorescence. These findings demonstrate that controlled RhB hybridization effectively tunes the emission spectrum of hbCQDs, offering a simple and reproducible strategy to achieve dual-color and white-light emission. The optimized hbCQDs/RhB composites hold significant potential for applications in hydrophobic media-compatible organic optoelectronics, light-emitting devices, and bioimaging.

Abstract: Polyaniline-cadmium sulfide-gold (PANI-CdS-Au) nanocomposites were synthesized with varying Au loadings (0.023, 0.046, 0.092)wt% to enhance antibacterial performance. Structural (FTIR, XRD) and morphological (FE-SEM) analyses confirmed successful formation, strong interactions among components, and homogeneous nanoparticle dispersion. UV–Vis spectra revealed gold surface plasmon resonance and polaronic transitions consistent with PANI emeraldine base. XRD results showed the expected wurtzite CdS and fcc Au phases. Agar well diffusion tests against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) demonstrated that the 0.092 wt% of Au composite produced the largest inhibition zones at 100 µg mL⁻¹ (E. coli: 36 mm; S. aureus: 24 mm), with the same trend at 25 µg mL⁻¹. These results position PANI-CdS-Au nanocomposites as promising antibacterial materials; additional cytotoxicity assays are recommended for biomedical translation.

Abstract: Background/Objectives: Essential oils (EOs) have multi-target antifungal activity, but their translation is limited by volatility and poor aqueous dispersibility. Randomly methylated β-cyclodextrin inclusion (RAMEB) may enhance effective exposure and thereby alter susceptibility, stress responses, and biofilm outcomes in a species-dependent manner. This study quantified species-specific planktonic and biofilm susceptibility to four EOs and their RAMEB complexes across clinically relevant Candida species. Methods: Lavender (L), lemon balm (B), peppermint (P), and thyme (T) oils and their RAMEB complexes (RL, RB, RP, RT) were tested against C. albicans, and non-albicans Candida. Susceptibility thresholds were used to derive phase plasticity metrics. Functional inhibition was assessed via planktonic metabolism/viability and established-biofilm metabolism/viability/biomass. Mechanistic signatures were captured by ROS/RNS measurements and qPCR of antioxidant genes (CAT1, GPX1, SOD1). Mixed-effects models and multivariate/unsupervised and interpretable classification approaches (k-means, PCA, CRT) were used to integrate endpoints and stratify response phenotypes. Results: Susceptibility thresholds were strongly species-structured (lowest MIC90/EC10 for C. albicans; higher thresholds and broader sublethal windows in non-albicans species). RAMEB complexation produced formulation-dependent shifts in efficacy, with RT emerging as the most consistent broad-spectrum inhibitory condition across compartments. Biofilm biomass was comparatively insensitive even when viability was suppressed, indicating decoupling of structural biomass from biocidal activity. Mechanistic signatures were broadly conserved across species and linked to antioxidant-program engagement, with CAT1-related rules contributing to responder/tolerant classification. Conclusions: Integrating MIC/EC plasticity with functional and mechanistic markers supports rational selection of EO formulations; RAMEB complexation particularly RT prioritizes candidates for further pharmaceutical optimization while highlighting species-specific vulnerabilities.

Abstract: Understanding the interactions of nanomaterials with complex tumour models is essential for advancing their use in nanomedicine. Calcium fluoride nanoparticles doped with neodymium and yttrium (CaF₂:Nd³⁺, Y³⁺) exhibit promising properties for biomedical applications, particularly for optical sensing and tagging. This study investigates their interaction with 3D cell spheroids derived from breast cancer (MCF-7) and brain cancer (U-87 MG) cell lines as tumour models. Specific protocols have been developed in Total-reflection X-Ray Fluorescence (TXRF) to evaluate nanoparticles’ internalisation and diffusion within spheroids by quantifying the concentrations of Ca, Nd, and Y taken up by the cells. Minimal background interference enabled precise multi-element detection in low-volume biological samples, yielding very low detection limits and minimal uncertainties. The study demonstrates the effectiveness of TXRF for quantifying rare-earth-doped nanoparticles in 3D cancer models and reveals that, although both cell lines permit nanoparticle diffusion into cells, higher accumulation is observed in glioblastoma cell spheroids. A Weibull diffusion model was applied to help understand the observed internalisation kinetics of nanoparticles into U-87 MG and MCF-7 spheroids. The relevant differences suggest cell-line-dependent uptake behaviour, potentially influenced by differences in cellular architecture, the porosity of the generated spheroid, and its intercellular 3D microstructure. These findings highlight the importance of tumour-specific interactions in the investigation of nanoparticle systems for targeted cancer diagnostics and therapeutics.

Abstract: Perovskite oxide photoanodes are attractive for alkaline water oxidation but are commonly limited by interfacial recombination and sluggish charge transfer. Here we enhance anisotropic SrTiO₃ (STO) photoelectrodes via Al doping and identify an optimal composition at 4% Al. In 0.1 M NaOH (pH 13) under simulated AM 1.5G illumination, 4% Al:STO exhibits the highest transient/steady photocurrent and the best LSV performance among all samples, together with a markedly reduced interfacial impedance, indicating accelerated charge extraction and transfer. High-resolution XPS confirms Al incorporation and reveals suppressed Ti3⁺-related defect states with modified oxygen-associated surface species, consistent with mitigated trap-assisted recombination. Band-structure analysis shows a negative shift in flat-band potential and slight band-gap narrowing after Al doping, providing more favorable carrier energetics. Steady-state and time-resolved photoluminescence further demonstrate strong PL quenching and prolonged carrier lifetime for 4% Al:STO. ECSA analysis suggests increased electrochemically accessible surface sites at the optimal doping level. Overall, moderate Al doping synergistically tunes defects, band energetics, and interfacial kinetics to improve STO photoanodes for solar water splitting.

Abstract:

Electrospinning and electrospraying nanotechnologies were used to valorise agro-industrial residues into biohybrid controlled-release polyphenol (CRP) scaffolds. Four polyhydroxybutyrate ± polycaprolactone (PHB±PCL) architectures were fabricated that differed in polymer phase, Klason lignin from hazelnut-shell (HS-KL) presence vs absence and co-location with grape-pomace polyphenols (GP-PP), as well as distribution between fibres and bead-like depots. Scaffolds were characterised using optical microscopy/stereomicroscopy/SEM, FTIR, UV/VIS spectroscopy and dynamic water contact angle (absorption). GP-PP release was monitored for 14 days at ~25 °C and 37 °C, the latter representing shallow-soil hot-spell conditions in Mediterranean zones. All matrices exhibited multimodal release, with modest initial bursts and three phases (burst, mid, and late tail), analogous to controlled-release fertiliser profiles. At ~25 °C, the PHB/PCL matrix with HS-KL confined to PHB fibres and GP-PP in large PCL beads showed the highest total GP-PP release, whereas the architecture with HS-KL and GP-PP co-located in both PHB and PCL fibres and in PCL depots combined high total release with a smoother, well-metered late phase. At 37 °C, this HS-KL-GP-PP co-located scaffold was the most robust, retaining the highest total and late tail release. These results identify HS-KL-GP-PP co-located PHB/PCL architectures as promising carriers for temperature-resilient delivery of bioactive polyphenols in Mediterranean agrosystems.

Abstract: Zinc oxide nanoparticles (ZnO NPs) have attracted significant attention due to their distinctive physicochemical characteristics and growing relevance across biomedical, environmental, and industrial domains, prompting sustained research into their design and functional performance. This review systematically examines reported synthesis approaches for ZnO nanoparticles, alongside commonly employed characterization techniques used to evaluate their structural, optical, and surface properties, with emphasis on how these parameters influence biological interactions. The article consolidates findings from recent studies describing the antimicrobial, anticancer, and drug-delivery-related functionalities of ZnO nanoparticles, highlighting proposed mechanisms such as reactive oxygen species generation, surface-mediated interactions, and controlled payload release. Additionally, the review summarizes existing evidence regarding biocompatibility, toxicity concerns, and stability issues that currently limit translational implementation. Collectively, the analyzed literature indicates that controlled synthesis and surface engineering play a critical role in tailoring ZnO nanoparticle performance for specific biomedical applications. In conclusion, this review identifies key challenges and emerging opportunities associated with ZnO nanoparticles and underscores the need for standardized evaluation frameworks and mechanistic clarity to support their responsible integration into future healthcare technologies.

Abstract: Upconverting nanoparticles, which transform low-energy infrared radiation into high-energy visible or UV light, show great potential in today’s technology. High-quality upconversion colloid (UCC) consisting of lanthanide-based nanoparticles with a diameter of ~10 nm was obtained using a combination of two processes, high-temperature coprecipitation and hydrothermal treatment in an autoclave. The UCC was then PEGylated with PEG-alendronate (PEG-Ale) to facilitate its dispersion in aqueous cell culture media intended for in vitro cell uptake assays. The surface modification of the nanoparticles increased both the colloidal stability in water and the upconversion emission by mitigating surface quenching. UCC@Ale-PEG was characterized by transmission and scanning electron microscopy, dynamic light scattering, and by fluorescence microscopy detecting upconversion photoluminescence emission. The results of an in vitro assay revealed that this new generation of UCC can be internalized by various cell types including epithelial cells, macrophages, and glioma cells, upon several hours of exposure, suggesting broad application potential of this type of UCC in biomedicine, bioengineering, and environmental sciences.

Abstract: In this study the photocatalytic activity as a function of effective irradiance, photocatalytic quantum yield and reactant coverage was thoroughly assessed for the proper photoreactor (PhR) selection. PhR selection is a preponderant stage for photocatalytic processes, which has been an aspect not studied in detail in various scientific investigations. The emitted wavelength and effective irradiance of several PhRs, equipped with fluorescent and light emitting diodes (LEDs) lamps, were tested in the photodegradation of methylene blue (MB) in solid phase using AgTiC. Among all tested PhRs the one equipped with the low-pressure Hg lamp enhanced the photodegradation of MB. The above is due to the Hg lamp emitted UV-type radiation, which promotes the simultaneous photoactivation of the TiO2 and the surface plasmon resonance phenomenon of the Ag nanoparticles. Based on this study, it was determined that high values of effective irradiance promoted photocata-lytic activity because of the greater amount of photogenerated species [e-/h+]. Also, the ef-fective irradiance on the proper photocatalytic material slows down the recombination rate of the [e-/h+]. A kinetic photocatalytic model (KPM) was proposed to the description of photocatalytic reactions as a function of the effective irradiance, photocatalytic quantum yield and reactant coverage considering photocatalytic pseudo steady state according to the reactant equilibrium coverage (Langmuir isotherm) and the transfer processes of the photoinduced charge carrier species.

Abstract: Ni@TiO₂ core–shell nanoparticles were synthesized by magnetron sputtering and their structure verified by HRTEM and EDS analysis. The thermal stability of these particles was investigated using in situ TEM annealing and compared with that of pure Ni nanoparticles. While pure Ni particles sinter already at 450 °C and exhibit significant growth at 800 °C, Ni@TiO2 nanoparticles remain stable up to 700 °C, with the sintering onset between 700 and 800 °C. A simple thermal-mismatch model was applied to explain the stabilizing effect of the TiO2 shell, demonstrating that differences in thermal expansion between Ni and TiO2 generate interface stresses sufficient to crack the shell after the amorphous–rutile transformation. The TiO2 coating effectively delays Ni coalescence by 250 °C relative to bare Ni, highlighting its role as a protective shell against high-temperature sintering.

Abstract:

Bacterial cellulose (BC) is an attractive biopolymeric scaffold for the development of functional membranes due to its high purity, nanofibrillar network, mechanical robustness, and biocompatibility. In this work, we report the production and characterization of BC membranes functionalized with silver nanoparticles (AgNPs) generated through a plant-mediated green synthesis strategy, with particular emphasis on maximizing nanoparticle incorporation within the BC matrix. Mint (Mentha spicata) and avocado (Persea americana) extracts were employed as dual reducing and stabilizing agents for AgNP formation, enabling nanoparticle synthesis under mild and environmentally benign conditions. AgNP formation was first investigated in aqueous media as a function of silver precursor concentration, pH, and temperature, and monitored by UV–Vis spectroscopy through localized surface plasmon resonance (LSPR) features. Neutral pH (pH 7) and moderate temperature (23 °C) were identified as optimal conditions, yielding well-defined LSPR indicative of efficient and controlled nanoparticle formation. Two strategies for BC functionalization were subsequently compared: post-synthesis immersion of BC membranes in AgNP suspensions and in situ synthesis of AgNPs directly within the BC network. Spectroscopic analysis demonstrated that in situ synthesis enables significantly higher effective nanoparticle loading and a more homogeneous distribution throughout the BC scaffold, compared with the immersion approach.The resulting BC–AgNP composite membranes were subsequently evaluated for their antibacterial efficacy against Escherichia coli. Antibacterial performance was assessed using two complementary experimental stups. In the first, composite membranes were placed on agar surfaces uniformly seeded with E. coli, and the diameter of the resulting inhibition zones was measured following a defined incubation period as an indicator of bacteriostatic and bactericidal activity. In the second model, the BC–AgNP membranes were directly introduced into liquid cultures of E. coli, and bacterial growth was quantified by measuring the optical density (OD) of the cultures after incubation. This dual assay approach allowed for evaluation of both surface- mediated inhibition and the effects of AgNP release on planktonic bacterial growth. Membranes functionalized via in situ synthesis exhibited markedly enhanced antibacterial activity, with larger growth-inhibition zones and the absence of bacterial regrowth in both solid and liquid assays, confirming a predominantly bactericidal effect. Overall, this study demonstrates that combining bacterial cellulose with in situ green synthesis of silver nanoparticles is an effective strategy to maximize nanoparticle incorporation and produce robust antimicrobial membranes, offering strong potential for applications in wound dressings, filtration systems, antimicrobial packaging, and other sustainable functional materials.

Abstract: The accurate monitoring and dynamic analysis of metal ions are of considerable practical significance in environmental toxicology and life sciences. Colorimetric analysis and surface-enhanced Raman scattering (SERS) sensing technologies, utilizing the aggregation effect of gold and silver nanoparticles (Au/Ag NPs), have emerged as prominent methods for rapid metal ion detection, serving as effective complements to conventional bulky instrumental analysis techniques. This is propelled by their distinctive localized surface plasmon resonance (LSPR) response and electromagnetic field enhancement mechanisms. This article evaluates contemporary optical sensing methodologies utilizing aggregation effects and their advancements in the detection of diverse metal ions. It comprehensively outlines methodological advancements from nanomaterial fabrication to signal transduction, encompassing approaches such as biomass-mediated green synthesis and functionalization, targeted surface ligand engineering, digital readout systems utilizing intelligent algorithms, and multimodal synergistic sensing. Recent studies demonstrate that these techniques have attained trace-level identification of target ions regarding analytical efficacy, with detection limits generally conforming to or beyond applicable environmental and health safety regulations. Moreover, pertinent research has enhanced detection linear ranges, anti-interference properties, and adaptability for point-of-care testing (POCT), validating the usefulness and developmental prospects of this technology for analysis in complicated matrices.

Abstract: High-energy methods dominate the development of lipid nanoparticles but often require specialized equipment that increases production costs. Low-energy approaches, particularly those free of organic solvents, offer a promising alternative. This study aimed to obtain nanostructured lipid carriers (NLC) using a solvent-free, low-energy process combining microemulsification and phase inversion. Cetearyl alcohol and PEG-40 hydrogenated castor oil were selected as solid lipid and surfactant, respectively, the formulation and process were optimized through a Box–Behnken Design. Incorporation of ionic surfactant extended colloidal stability, while poloxamer in the aqueous phase enhanced steric stabilization. Resveratrol was efficiently encapsulated (E.E. = 98%), contributing to reduced particle size (291 nm), improved homogeneity (PDI = 0.25), and positive surface charge (+43 mV). Scale-up yielded stable particles carrying resveratrol with mean size of 507 nm, PDI = 0.24, and ZP = +52 mV. The optimized formulation remained stable for 90 days at 8 °C. In vitro release demonstrated a sustained and controlled release profile, with significantly lower resveratrol release compared to the free compound. Thermal analysis confirmed drug incorporation within the lipid matrix, while transmission electron microscopy (TEM) revealed spherical particles (~200 nm) and SAXS indicated a nanostructure of ~50 nm. Overall, this study demonstrates that solvent-free, low-energy processing can produce stable and scalable NLC formulations, successfully encapsulating resveratrol with favorable physicochemical properties and controlled release behavior. These findings highlight a simple, cost-effective strategy for developing lipid-based nanocarriers with potential applications in drug delivery.

Abstract: Background: Boron Neutron Capture Therapy (BNCT) represents a highly selective therapeutic modality for recalcitrant cancers, leveraging the nuclear reaction initiated by thermal neutron capture in Boron-10 (10B) to deliver high-linear energy transfer radiation (α-particles and 7Li ions) directly within tumor cell boundaries. However, the widespread clinical adoption of BNCT is critically hampered by the pharmacological challenge of achieving sufficiently high, tumor-selective intracellular 10B concentrations (20-50 μg of 10B /g tissue). Conventional small-molecule boron carriers often exhibit dose-limiting non-specificity, rapid systemic clearance, and poor cellular uptake kinetics. Methods: To overcome these delivery barriers, we synthesized and characterized a novel dual-modality nanoplatform based on highly biocompatible, functionalized graphene oxide (GO). This platform was structurally optimized through covalent conjugation with high-boron content carborane clusters (dodecacarborane derivatives) to enhance BNCT efficacy. Crucially, the nanocarrier was further decorated with plasmonic gold nanostructures (AuNPs), thereby endowing the system with intrinsic surface-enhanced Raman scattering (SERS) properties, which enabled real-time, high-resolution intracellular tracking and quantification. Results: We evaluated the synthesized GO@Carborane@Au nanoplatforms for their stability, cytotoxicity, and internalization characteristics. Cytotoxicity assays demonstrated excellent biocompatibility against the non-malignant human keratinocyte line (HaCaT), while showing selective toxicity (upon irradiation, if tested) and high cellular uptake efficiency in the aggressive human glioblastoma tumor cell line (T98G). The integrated plasmonic component allowed for the successful, non-destructive monitoring of nanoplatform delivery and accumulation within both HaCaT and T98G cells using SERS microscopy, confirming the potential for pharmacokinetic and biodistribution studies in vivo. Conclusion: This work details the successful synthesis and preliminary in vitro validation of a unique Graphene Oxide-based dual-modality nanoplatform designed to address the critical delivery and monitoring challenges of BNCT. By combining highly efficient carborane delivery with an integrated photonic trace marker, this system establishes a robust paradigm for next-generation theranostic agents, significantly advancing the potential for precision, image-guided BNCT for difficult-to-treat cancers like glioblastoma.

Abstract:

This study presents a novel membrane-inspired Ag₂Mo₃O₁₀·1.8H₂O/carbon fiber cloth (CFC) hybrid framework designed for the continuous and selective recovery of high-value sulfur-containing molecules from organic wastewater. The framework was fabricated by uniformly growing Ag₂Mo₃O₁₀·1.8H₂O nanowires on CFC membrane, forming a hierarchical porous network with abundant micro-nano channels that facilitate efficient, capillary-driven water transport. Owing to its mesoporous structure and specific Ag-S coordination affinity, the material exhibits excellent selectivity for sulfur-containing dyes, achieving rapid adsorption (>94% removal of methylene blue within 10 minutes) and high specificity in mixed solutions. Moreover, the hybrid framework demonstrates outstanding reusability, retaining high recovery efficiency over multiple cycles. A continuous-flow system based on this framework operates without external pressure and achieves a water transport rate of 1875 mL·h^-1·m^-2. These results underscore the potential of the Ag₂Mo₃O₁₀·1.8H₂O/CFC system as an efficient, scalable, and sustainable platform for industrial wastewater resource recovery.

Abstract: In this work, we evaluate the efficiency of a DNA purification protocol from gynecological samples using locally synthesized Fe₃O₄@SiO₂ magnetic microparticles and a low-cost, guanidinium thiocyanate (GITC)-free lysis buffer. The microparticles were characterized by SEM, EDS, FTIR, and magnetic measurements, confirming the formation of compact silica-coated aggregates with suitable magnetic responsiveness for rapid and complete capture. Using this material in combination with a simple, GITC-free lysis buffer, we achieved DNA extraction yields comparable to those obtained with standard methods based in chaotropic salts. The purified DNA showed high compatibility with molecular assays for the detection of Chlamydia trachomatis, Ureaplasma urealyticum, Mycoplasma hominis, and human papilloma virus. Clinical validation demonstrated excellent diagnostic performance, with only a few discrepancies observed in samples near the detection threshold of qPCR, a limitation shared with commercial kits. Overall, the method represents a low-cost, safe, and sustainable alternative for routine clinical and epidemiological applications, compared to those methods based on cha-otropic salts buffers. Furthermore, it reduces reliance on imported commercial consuma-bles and minimizes the handling of hazardous reagents.

Abstract: Scanning electron microscopy (SEM) is a powerful tool for the morphological characterization of multiscale nanomaterials, including two-dimensional (2D) systems such as graphene and molybdenum disulfide (MoS₂). However, conventional SEM imaging often struggles to resolve nanoscale features due to limited contrast and depth sensitivity, especially when dealing with ultrathin layers. In this work, we propose and demonstrate a simple yet effective strategy to overcome these limitations by exploiting grazing-incidence (radent) observation, achieved through a controlled tilting of the sample close to 90°. This approach significantly enhances the emission of secondary electrons from near-surface regions, thereby increasing image contrast and revealing morphological details, such as edges, ripples, defects, and overlapping layers, that remain hidden under standard imaging conditions. Optical characterization of the prepared MoS₂ colloids further supports the formation of monolayer and few-layer sheets, validating the structural information obtained from SEM. Interestingly, this approach recalls natural strategies observed in living organisms, where grazing-angle vision improves edge perception and surface recognition and therefore it can be considered as bio-inspired. Beyond its use with MoS₂, this biomimetic methodology offers a versatile and broadly applicable solution for improving morphological analysis of 2D nanomaterials and thin films, providing deeper insights into their structural characterization.

Abstract: Nano Metal–Organic Frameworks (nMOFs) have emerged as a versatile class of porous materials with significant potential in biomedical applications, particularly in cancer treatment. This review explores the pivotal role of nMOFs in facilitating the combina-tion of photodynamic therapy (PDT) and immunotherapy (IMT), focusing on their unique capabilities to synergistically enhance therapeutic outcomes. By serving as effi-cient photosensitizer and immunotherapy drug carriers nMOFs serve as immune re-sponse modulators and enable targeted tumour destruction through reactive oxygen species generation while simultaneously stimulating antitumor immunity. The com-bination of nMOF-based PDT and immunotherapy represents a promising strategy for more effective, personalized cancer treatments. This article highlights recent progress, challenges, and future perspectives in leveraging nMOFs for the synergistic cancer therapy landscape.

Abstract: Carbon quantum dots (CQDs) have emerged as highly versatile nanomaterials due to their tunable optical properties, excellent water dispersibility, and chemical stability. In this work, undoped, N-doped, and N,S-doped CQDs were synthesized via a simple, low-temperature bottom-up method using different molecular additives to tailor their emission behavior. Systematic characterization by UV–Vis spectroscopy, photoluminescence (PL), and quantum yield measurements (QY) confirmed that heteroatom doping effectively modulates the electronic structure of CQDs, enabling controllable emission spanning the UV to visible region. Undoped CQDs exhibited excitation-dependent blue emission arising from surface states, whereas nitrogen doping introduced mid-gap states responsible for a pronounced red-shift and dual-band emission. Co-doping with nitrogen and sulfur further intensified defect-related blue emission, leading to a noticeable enhancement in photoluminescence intensity. In addition, the nitrogen-doped CQDs were successfully employed as a sensitive fluorescent probe for Fe³⁺ ion detection. The CQDs exhibited high selectivity toward Fe³⁺ with significant fluorescence quenching, attributed to strong coordination between Fe³⁺ ions and surface functional groups. The sensing performance was optimized by studying the effects of pH, reaction time, and Fe³⁺ concentration, revealing a rapid response within 5 minutes and effective operation over a wide pH range (3–11) with maximum quenching at pH 7. A linear Stern–Volmer relationship was observed between quenching efficiency and Fe³⁺ concentration (1–200 μM), demonstrating the suitability of N-CQDs for quantitative detection. Overall, this study highlights the ability to tune CQD emission through controlled heteroatom doping and demonstrates the practical potential of N-doped CQDs as a simple, sensitive, and selective fluorescent sensor for Fe³⁺ ions in aqueous environments.