Chemistry and Materials Science

Abstract: Industrial synthetic dyes represent a major source of water pollution because current treatment methods fail to remove them efficiently prior to discharge. Consequently, developing cost-effective and highly efficient technologies for wastewater systems is essential. Adsorption satisfies these demands and easily couples with other industrial effluent treatments. This study focuses on nanoporous anodic aluminum oxide (AAO), an outstanding adsorbent known for its versatility, high specific surface area, significant porosity, and thermal stability. Although the adsorption capacity of this nanoadsorbent has been recently studied, this work specifically evaluates the performance of AAO modified through different thermal and chemical treatments for the removal of Eriochrome Black T from aqueous solutions. Within a 1-h process, the applied treatments significantly enhanced AAO adsorption performance: standalone calcination and chemical etching led to a 10% increase in dye removal efficiency, while combining calcination with alkaline etching resulted in a 38% improvement. Furthermore, the combined treatment was demonstrated to enhance the adsorption process at alkaline pH levels (up to pH 10), and the modified AAO could be reused up to four times while maintaining a significantly high removal efficiency. Finally, this study provides key insights into the underlying phenomena governing the adsorption of anionic dyes onto AAO nanostructures.

Abstract: Surface-enhanced Raman spectroscopy (SERS) has emerged as a highly promising analytical technique for disease diagnostics due to its exceptional sensitivity, molecular specificity, and ability to detect a broad range of biomarkers in complex biological matrices. This review provides a comprehensive overview of gold- and silver-nanoparticle-based SERS platforms for plasma disease diagnostics, covering advances in plasmonic nanostructures, biological sample analysis, biomarker detection, and AI-driven spectral data processing. Particular emphasis is placed on the application of SERS to clinically relevant biofluids, especially plasma, where the technique has demonstrated considerable potential for detecting diseases such as cancer, inflammatory disorders, and neurological conditions. The review also critically examines the major challenges currently limiting the clinical translation of SERS technologies. These include variability associated with substrate fabrication, matrix-induced signal fluctuations, limited interlaboratory reproducibility, and the lack of standardized protocols for spectral preprocessing and data analysis. Strategies proposed to address these issues are discussed, including comprehensive post-synthesis substrate characterization, optimization of biological sample preparation, advanced spectral preprocessing workflows, and the integration of machine learning and artificial intelligence algorithms to improve diagnostic robustness and reproducibility. Collectively, the advances summarized in this review indicate that SERS-based diagnostic technologies are rapidly progressing beyond proof-of-concept studies toward clinically applicable systems. Continued interdisciplinary collaboration and standardization efforts will be essential to bridge the remaining gap between experimental SERS methodologies and routine clinical implementation.

Abstract: Background: Actinium-225 (²²⁵Ac) is receiving major attention as the radionuclide of choice for targeted alpha therapy (TAT) due to its outstanding physical properties such as a long physical half-life of 9.9 days and a short range of alpha (α)- particles which are responsible for the destruction of malignant tumours, whilst sparing normal surrounding tissues. Although the physical properties of ²²⁵Ac make it a desirable radionuclide for TAT, its application is challenging due to the lack of chelators available to stabilise its daughter radionuclides, resulting in the recoil effect. This occurs when there is a breakdown between the radionuclide and the chelator, therefore minimising the therapeutic effects of the radiopharmaceutical. Nanodrug delivery systems (NDDS) may minimise the challenge of ²²⁵Ac’s recoiling daughters and increase tumour penetration. Aim: This study aimed at using poly(lactic-co-glycolic)acid (PLGA) and chitosan nanoparticles as a delivery vehicle for targeted alpha therapy of prostate cancer in order to increase the therapeutic effect of ²²⁵Ac PSMA617-TFA. Methods and Results: PLGA nanoparticles were prepared using a nanoprecipitation method, after which they were functionalised with chitosan and folic acid. Following synthesis of ²²⁵Ac PSMA617-TFA, the radiopharmaceutical was loaded onto the nanoparticles. SEM analysis and FTIR were performed for characterisation of the nanoparticles and in-vitro drug release of ²²⁵Ac PSMA617-TFA at pH= 6.5 and pH= 7.4, respectively was done. The nanoparticles prepared were an average size of 200nm and had a positive charge. This was further confirmed using a zetasizer and with Scanning Electron Microscope (SEM) analysis. The PLGA-Chitosan nanoparticles indicated a high encapsulation efficiency after 24 hours. The results also showed a controlled release of ²²⁵Ac PSMA617-TFA over 72 hours. The results of this study indicate that PLGA-Chitosan nanoparticles are suitable for retaining ²²⁵Ac and its recoiling daughters (221Fr and 213Bi) at the tumour site, potentially increasing the therapeutic potential of ²²⁵Ac PSMA617-TFA. Conclusion: PLGA-Chitosan nanoparticles may be a suitable drug delivery vehicle of ²²⁵Ac PSMA617-TFA that can deliver into solid tumours and retain the recoiling daughters within the tumour site.

Abstract: The development of support for the immobilization of enzymes and yeasts is an important step in hydrolysis and fermentative processes, aiming to recover and reuse biocatalysts, thereby making the process of bioethanol production economically viable. In this study, we propose a core/shell support made of nanomagnets armed with Saccharomyces cerevisiae cells as a nanobiocatalyst for fermentative processes. We use orange biomass, a common waste in Brazil, for bioethanol production. The produced nanomagnets had a zeta potential of +28.0 ± 0.5 mV, were efficiently covered by silica and armed with -NH2 groups, and were duly characterized by infrared spectroscopy. The biomass after acid hydrolysis presented 10 ± 0.6 g L-1 of reducing sugars, which were quantified using the colorimetric method. An evaluation of fermentation conditions was carried out by varying temperature and pH. In the first condition, the achieved ethanol yield was 35-46% after 48 h of fermentation, while in the second condition, we obtained 48-90% ethanol, and in the third condition, 50-69.2%. The produced bioethanol was quantified through a chemical oxidation reaction. The immobilization process proved to be satisfactory with a reaction yield of around 25-30%.

Abstract: Background/Objectives: One of the ongoing clinical constraints is limiting microbial growth on facial and dental prostheses, justifying the need for material surface enhancements for reducing the associated microbial complications. This study aimed to investigate a clinically applicable and reproducible coating technique to overcome microbial clinical challenges. Methods: Ag nanoparticles (NPs) were applied to three types of facial materials through spray, spin, and dip coating techniques. Surface characterization, elemental composition, and chemical bond formation were assessed by Scanning Electron Microscopy (SEM), Energy-dispersive X-ray Spectroscopy (EDS), and Fourier Transform Infrared (FTIR) spectroscopy, respectively. Subsequent optimization of spray numbers was performed. Antimicrobial performance was examined by agar diffusion, direct contact, and adhesion (time-dependent) assays, with different layers, against Pseudomonas aeruginosa. Results: Spray coating exhibited superior coating uniformity compared with others. 15 sprays was determined as optimal number for a single layer coating. EDS confirmed Ag NP presence, FTIR revealed no chemical alteration of specimens. Disk diffusion tests showed no inhibition zones. Adhesion and direct contact tests displayed antibacterial activity, the effect of which was stronger for the latter. Time-dependent adhesion test of 1-layer coating of acrylic and silicone had a consistent decrease in bacterial amount, whilst zirconia had only a strong initial activity. In general, the 3-layer coating did not showcase an increased antimicrobial activity, suggesting that the increase in layering negatively impacts surface effectiveness. Conclusions: spray coating of Ag NPs can provide a promising, clinically-applicable, large-scale manufacturing strategy for improving dental and facial material antibacterial qualities without altering the inherent prosthetic properties.

Abstract: Electrospinning is a relatively easy and perspective method for producing polymeric, ceramic, and composite fibers, which may vary from several nanometers to several micrometers. Poly(vinyl alcohol) (PVA) is a water-soluble, non-toxic, and biocompatible polymer with good mechanical properties, making it widely used for electrospinning. In this study, the influence of PVA solution concentration, applied voltage, tip-to-collector distance, and needle size on the morphology and diameter of the obtained fibers was investigated in order to optimize the conditions for the production of bead-free nanofibers. For this purpose, PVA solutions with different concentrations (5, 7.5, and 10 wt.%) were prepared and electrospun by altering the parameters of the process. Fiber morphology and diameter distribution as a function of the studied parameters were evaluated by Scanning electron microscopy (SEM). The results demonstrated a strong dependence of fiber morphology on solution viscosity. At low concentration (5 wt.%), fibers with numerous bead defects were obtained. Increasing the concentration to 7.5 wt.% led to a significant reduction in bead defect. Further increasing the concentration up to 10 wt.% led to the production of smooth and homogeneous fibers under the optimized conditions. A non-linear relationship between fiber diameter and tip-to-collector distance was observed, with an optimal distance of 140 mm yielding the thinnest and most uniform fibers. Additionally, needle diameter was found to influence both fiber size and process stability. Smaller needle diameters (G22) enabled the production of finer fibers (~180 nm), but with increased sensitivity to processing conditions, whereas larger diameters (G20–G21) provided more stable jet behavior and narrower diameter distributions. The statistical analysis ANOVA confirmed these findings. The study provides useful insights for optimizing electrospinning parameters to obtain high-quality, bead-free PVA nanofibers.

Abstract: Oral drug delivery remains the most preferred route of administration; however, traditional oral dosage forms face several limitations, including low bioavailability, enzymatic degradation, poor permeability, and lack of site-specific drug release. Recent advances in nanotechnology have introduced nanoparticles as promising drug carriers capable of overcoming these challenges. Eudragit-based nanoparticles have demonstrated great potential in enhancing drug stability, controlling release profiles, and improving site-specific targeting in the gastrointestinal tract. These polymethacrylate copolymers exhibit pH-dependent solubility, mucoadhesive properties, and tuneable drug-loading capacities, making them highly suitable for advanced oral formulations. This review provides a comprehensive analysis of Eudragit®-based nanoparticulate systems for oral drug delivery, discussing their formulations, physicochemical properties, and mechanisms of controlled drug release. Emphasis is placed on controlled-release strategies, targeted delivery, and the impact of polymeric materials in optimising therapeutic outcomes. By exploring these aspects, this review aims to highlight the potential of Eudragit-based nanoparticles as a robust platform for improving oral drug bioavailability and efficacy.

Abstract: The development of biocompatible functional nanostructures has emerged as a key driver in advancing nanomedicine, environmental remediation, and sustainable energy technologies. However, conventional synthesis methods often rely on toxic reagents, hazardous solvents, and energy-intensive processes, raising significant concerns regarding environmental impact and biological safety. In this context, green synthesis has gained increasing attention as a sustainable alternative, utilizing biological systems, renewable resources, and environmentally benign solvents to produce functional nanomaterials. This mini-review provides a comprehensive overview of recent advances in the green synthesis of organic, inorganic, and hybrid nanostructures, highlighting their physicochemical properties and functional performance. Particular emphasis is placed on their applications in nanomedicine, including drug delivery, bioimaging, antimicrobial and anticancer therapies, and theranostic platforms. Additionally, their roles in environmental applications, such as pollutant degradation and water treatment, and in energy-related systems, including catalysis, solar energy conversion, and energy storage, are critically discussed. Despite significant progress, key challenges remain, including limited mechanistic understanding, reproducibility issues, scalability constraints, and uncertainties related to long-term toxicity and environmental impact. Addressing these limitations will be essential for the safe and large-scale implementation of green nanotechnology. Overall, the integration of green chemistry principles with advanced nanomaterial design offers a promising pathway toward the development of multifunctional, sustainable, and high-performance nanostructures capable of addressing global health, environmental, and energy challenges.

Abstract: Antibiotic contamination of water, particularly tetracycline (TC), poses significant environmental risks and requires sustainable treatment solutions. This study reports a green and cost-effective synthesis of a ZnO/chitosan nanocomposite (ZnO/CS) for photocatalytic TC removal. ZnO nanoparticles were synthesized using lime juice as a natural stabilizing agent and subsequently incorporated into a chitosan matrix. The physicochemical properties of the composite were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), UV–Vis diffuse reflectance spectroscopy (UV–Vis DRS), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller (BET) surface area analysis. The results confirmed the formation of hexagonal wurtzite ZnO and strong interfacial interactions between ZnO and the –NH2/–OH groups of chitosan. A red shift reduced the band gap from 3.18 to 3.03 eV, while the specific surface area increased from 10.7 to 21.7 m² g⁻¹. Under LED irradiation, the ZnO/CS nanocomposite achieved 94% TC removal within 120 min, following pseudo-first-order kinetics based on the Langmuir–Hinshelwood model. These findings demonstrate the potential of the green-synthesized ZnO/CS nanocomposite for antibiotic removal from aqueous environments.

Abstract: Industrial dye wastewater poses severe environmental and health risks, creating an urgent demand for efficient and sustainable remediation technologies. Herein, hierarchically porous hollow TiO2 nanofibers (HNFTi) were constructed through electrospinning and coupled with blue-, green-, and orange-emissive graphene quantum dots (b-, g-, and o-GQDs) to fabricate visible-light-responsive heterojunction photocatalysts. By tailoring the surface functional groups and heteroatom doping of GQDs, a progressive fluorescence redshift was achieved, which effectively narrowed the bandgap and extended visible-light absorption. Benefiting from the synergistic effects of the hierarchically porous hollow TiO2 architecture and the fluorescence-tuned GQDs, the resulting composites exhibited enhanced light harvesting, accelerated charge separation, and improved interfacial charge transfer. Among them, the 0.5 wt% o-GQDs/HNFTi composite showed the best photocatalytic performance, delivering a methylene blue degradation efficiency of 99.5% within 2 h under visible-light irradiation, markedly higher than that of pristine HNFTi (77.7%). Photoelectrochemical and Kelvin probe force microscopy analyses further confirmed the promoted carrier dynamics and effective interfacial separation of photogenerated electron-hole pairs. This work provides a feasible strategy for integrating structural engineering and fluorescence modulation to develop high-performance TiO2-based photocatalysts for wastewater treatment.

Abstract: Cancer remains a major global health challenge, and the limitations of conventional therapies have intensified interest in treatment strategies that combine improved selectivity with reduced systemic toxicity. Photothermal therapy and photodynamic therapy have emerged as minimally invasive approaches capable of achieving spatiotemporally controlled tumour ablation. In this context, molybdenum disulfide (MoS₂), a transition metal dichalcogenide with strong near-infrared absorption, high photothermal conversion efficiency, and versatile surface chemistry, has gained increasing attention as a multifunctional platform for drug delivery and light-triggered cancer therapy. This review examines recent advances in engineered MoS₂ nanoplatforms for drug-enhanced cancer phototherapy, with emphasis on how surface design and therapeutic cargoes mechanistically amplify light-triggered tumour killing. Approaches such as polymer coatings, biomimetic membranes, targeting ligands, chemotherapeutic agents, nucleic acids, and photosensitisers have been explored to improve colloidal stability, tumour targeting, immune evasion, and stimulus-responsive drug release, while also adding complementary cytotoxic pathways such as chemotherapy, ROS generation, or gene silencing. Available in vitro and in vivo studies indicate that these systems generally exhibit favourable short-term biocompatibility under the tested conditions and can produce significant antitumour effects following irradiation. The review also discusses key biological barriers and translational challenges, including biodistribution, long-term safety, reproducibility, and regulatory considerations, highlighting opportunities for the development of clinically viable MoS₂-based phototherapeutic platforms.

Abstract: The performance and mechanism of heterogeneous catalytic reactions are fundamentally governed by the formation, stability, and reactivity of transient surface intermediates. These species—such as isocyanates, alkyl groups, carboxylates, formates, carbonates, alkoxy and acyl intermediates—often exist at low concentrations and with short lifetimes, making their identification challenging. This review summarizes current knowledge on the formation, spectroscopic identification, and thermal behavior of these intermediates on metal single crystals, metal nanoparticles, and oxide-supported catalysts. Emphasis is placed on key reactions including CO and NO oxidation–reduction, CO and CO₂ hydrogenation, Fischer–Tropsch–related pathways, and reforming of methane and light alcohols. Advanced surface-sensitive techniques (TDS, XPS, UPS, IR, HREELS) are highlighted for their role in elucidating intermediate structures and reaction pathways. The review also discusses how metal–support interactions, particle size, and surface morphology influence intermediate stability and catalytic selectivity. Overall, the work provides a comprehensive framework for understanding how transient surface complexes control technologically important catalytic transformations.

Abstract: Virus-like particles (VLPs) are self-assembling protein nanostructures that replicate the structural precision of viral capsids while lacking genetic material, rendering them inherently safe and highly modular biomaterials. Their genetically encoded architecture enables precise control over size, symmetry, mechanical stability, surface topology, and internal cavity volume, positioning VLPs as programmable protein-based nanocarriers for chemotherapeutic delivery. Recent advances in capsid engineering, biorthogonal conjugation, and template-guided assembly have enabled fine tuning of cargo loading, targeting ligand display, and stimuli-responsive drug release. Unlike many synthetic nanocarriers, VLPs offer atomically defined structure–function relationships, allowing rational modulation of biodistribution, cellular uptake, immune recognition, and therapeutic performance. This review examines VLPs as engineered protein biomaterials for precision chemotherapy, highlighting strategies for internal cargo integration, interfacial surface modification, mechanical reinforcement, and microenvironment-triggered release. Here we discuss how physicochemical parameters govern biological interactions and translational feasibility. Clinical progress underscores both the promise and remaining challenges of scalable manufacturing and immune modulation. By integrating biomaterials design principles with translational constraints, this review outlines a framework for the rational development of clinically viable VLP-based chemotherapeutic systems.

Abstract: Commercially available drug-eluting stents still suffer from poor blood compatibility, polymer coating delamination, cracking and lack of stability during and after stent implantation that led to adverse events such as stent thrombosis and in-stent restenosis. This article highlights the advantages of using silicon nanofilament (SiNf) as an interface between stent surface and drug-in-polymer coating or bloodstream. The SiNf was successfully formed on the surface of Co-Cr substrate via one-step simple method. The morphology of the filaments showed nanosized structures with nano-gaps between the filaments. After coating the nanofilaments with a mixture of sirolimus and poly(D,L-lactide), an interlocking mechanism was established in which the coating penetrates the nano-gapes between the filaments. Therefore, the presence of SiNf enhanced the coating stability with no coating delamination whereas, the control substrate presented 97% of coating delamination. For stent application, the SRL-in-PDLLA matrix was coated on stent platform with smooth and uniform morphology without webbing between stent struts. After stent ballooning, the control stent presented cracking and peeling of the polymer coating from the surface whereas, the SiNf-modified stent did not show any sign of these unfavorable defects. Moreover, the platelet adhesion on the SiNf surface showed a lower number with round shape morphology compared to control Co-Cr. This suggests that modifying the substrates with SiNf could act as a universal coating for reinforcing the polymer coating stability, prevent coating defects that accompany stent ballooning, and improve the blood compatibility of the material surfaces that could have various applications to medical implants and devices.

Abstract: Nanoparticles offer a versatile platform for the selective eradication of pathogenic or diseased cells by integrating therapeutic payload delivery with precision targeting. Precision targeting can be achieved (1) actively through ligand conjugation, (2) passively by exploiting the physiological abnormalities of diseased tissues, or (3) intrinsically through the innate biophysical properties of the nanoparticle. Intrinsically selective nanoplatforms (iNPs) are particularly advantageous when the disease-promoting agent does not possess distinct surface markers, such as in the case of certain “untargetable cancers” or cancers without known targets. Indeed, nanocarriers for chemotherapeutic or gene delivery have achieved selective cancer cell apoptosis without requiring marker presentation, thereby expanding the therapeutic window of the payload. Disease-promoting agents whose physical properties are different from those of healthy cells are also good candidates for intrinsic nanoparticle targeting. For example, antimicrobial nanomaterials have been designed to disrupt bacterial membranes and reduce the risk of antimicrobial resistance by leveraging stiffness differentials between bacterial cell walls and eukaryotic membranes. Nanoparticle systems with intrinsic targeting mechanisms can also enable non-invasive imaging with near-infrared fluorescence, MRI, and photoacoustic imaging for real-time biodistribution tracking and treatment monitoring. This review synthesizes current innovations in nanoplatform design with intrinsic targeting capabilities, spans applications in infectious and non-communicable diseases, and discusses emerging strategies to enhance specificity, overcome resistance, and translate these platforms toward clinical and field deployment.

Abstract: Green synthesis of metal-based nanomaterials has emerged as an eco-friendly alternative to conventional chemical routes due to its sustainability, cost-effectiveness, and reduced environmental impact. In the present study, nickel nitrate nanoparticles (Ni(NO₃)₂ NPs) were biosynthesized using Tridax procumbens leaf extract as a reducing and stabilizing agent. The formation of Ni(NO₃)₂ nanoparticles was confirmed through UV–Visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray analysis (EDAX). XRD analysis revealed the crystalline nature of the synthesized nanoparticles with a face-centered cubic structure, while SEM images showed agglomerated, quasi-spherical particles with rough and porous surfaces. FTIR analysis confirmed the involvement of plant-derived phytochemicals in nanoparticle stabilization. The biosynthesized Ni(NO₃)₂ nanoparticles exhibited significant antimicrobial activity against selected bacterial and fungal strains in a concentration-dependent manner. Furthermore, the photocatalytic performance of the nanoparticles was evaluated for the degradation of Yellow RGB Red Azo dye under visible light irradiation. The degradation efficiency was strongly influenced by pH and catalyst dosage, with maximum degradation (~98%) achieved at alkaline pH (10) and higher catalyst loading. Kinetic studies demonstrated that the dye degradation followed pseudo-first-order kinetics. Scavenger experiments revealed that hydroxyl and superoxide radicals played a dominant role in the photocatalytic degradation mechanism. The results highlight the potential of Tridax procumbens-mediated Ni(NO₃)₂ nanoparticles as efficient, sustainable materials for antimicrobial applications and wastewater treatment.

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.