Search Results (701)

Graphene oxide (GO) is a carbon-based nanomaterial explored for agricultural and forestry uses, but plant responses are strongly subject to both the dose and the route of exposure. We summarized recent studies with defined graphene oxide (GO) exposures by seed priming, foliar delivery, and root or soil exposure, while comparing annual crops with woody forest plants. Mechanistic progress points to a shared physicochemical basis: surface oxygen groups and sheet geometry reshape water and ion microenvironments at the soil–seed and soil–rhizosphere interfaces, and many reported shifts in antioxidant enzymes and hormone pathways likely represent downstream stress responses. In crops, low-to-moderate doses most consistently improve germination, root architecture, and tolerance to salinity or drought stress, whereas high doses or prolonged root exposure can cause root surface coating, oxidative injury, and photosynthetic inhibition. In forest plants, evidence remains limited and often relies on seedlings or tissue culture. For forest plants with long life cycles, processes such as soil persistence, aging, and multi-seasonal carry-over become key factors, especially in nurseries and restoration substrates. The available data indicate predominant root retention with generally limited root-to-shoot translocation, so residues in edible and medicinal organs remain insufficiently quantified under realistic-use patterns. This review provides a scenario-based framework for crop- and forestry-specific safe-dose windows and proposes standardized endpoints for long-term fate and ecological risk assessment. Full article

Nanomaterials are widely used in biomedical research as drug and antibody carriers, and some nanomaterials have been shown to exhibit antimicrobial activity. Previously, silver nanoclusters (AgNCs) were predicted to interact with the bacterial TolC protein, which is involved in the development of multidrug resistance in pathogens. In this study, glutathione-coated AgNCs were synthesized and characterized. Their toxicological properties were studied in a microplate assay against five bacterial strains, both as single components and in mixtures with heavy metal salts and antibiotics. The resulting AgNCs had a diameter of 2.2 ± 0.5 nm, with excitation and emission maxima of λ = 490 nm and λ = 638 nm, respectively. No significant growth inhibition was observed at the concentrations used in resistance modulation assays (≤2.5 µg/mL Ag), except for transient effects at very high concentrations. A decrease in bacterial resistance to copper (II) and cadmium (II) cations and the antibiotics erythromycin and levofloxacin was observed upon the addition of AgNCs containing 2.5 μg/mL silver to the nutrient medium. A dose-dependent effect of AgNCs on bacterial resistance to toxicants was established. Thus, nanoclusters can be considered as inhibitors of bacterial resistance to heavy metals and antibiotics, which may be useful in studying bacterial adaptation mechanisms and developing technologies for overcoming multidrug resistance in bacteria. Full article

We report a galvanic replacement-driven strategy for the in situ growth of highly uniform one-dimensional (1D) Cu@CuO-X (X = Ag, Bi) nanobelts directly on aluminum foils. Unlike conventional multi-step coating or hard-template replication strategies, the formation of these heterostructured nanobelts is governed by a spontaneous interfacial galvanic replacement process between Cu and the introduced metal species, ensuring in situ growth and intimate interfacial integration. Comprehensive SEM, TEM, XRD, and XPS characterizations confirm the successful formation of Cu@CuO-Ag and Cu@CuO-Bi architectures, where Bi predominantly exists in the oxidized Bi³⁺ state, forming Bi₂O₃-like surface species. Benefiting from their 1D anisotropic framework and controllable heterointerfaces, this work underscores the distinctiveness and versatility of the self-templated galvanic replacement strategy for the design of multifunctional nanomaterials. Full article

Multifunctional nanomaterials have been extensively investigated in theranostics to enhance therapeutic specificity, biocompatibility, and responsiveness to external magnetic gradients. We synthesized magnetoplasmonic nanocomposites comprising magnetite nanoparticles modified with gold and silver. Magnetite was synthesized via chemical co-precipitation and stabilized in an aqueous medium using glucose, which also served as a reducing agent for Au³⁺ and Ag⁺ ions on the nanoparticle surface. Microstructural, magnetic, spectral, and optical characterizations confirmed the successful formation of nanocomposites with properties suitable for biomedical applications. Plasmonic behavior was evidenced by visible-range absorbance maxima at 398 nm (Ag) and 538 nm (Au), while Transmission Electron Microscopy (TEM) revealed mean diameters of 21 and 23 nm. Zeta potential values of +23 mV for magnetite–silver and −40 mV for magnetite–gold nanocomposite samples indicated good suspension stability. Antibacterial activity against Gram-positive and Gram-negative bacteria was evaluated using agar diffusion and by determining the minimum inhibitory (MIC) and bactericidal (MBC) concentrations. Silver-modified magnetite nanocomposites exhibited the most potent effects, with MIC values of 0.01 mg/mL for Escherichia coli (E. coli) and 0.02 mg/mL for Staphylococcus aureus (S. aureus), and corresponding MBC values of 0.027 mg/mL and 0.055 mg/mL, respectively. These magnetoplasmonic nanostructures have significant potential for overcoming antibiotic resistance and enabling targeted therapeutic action through magnetic guidance. Full article

Thanks to both endogenous and exogenous antioxidants (AOs), the antioxidant defense system ensures redox homeostasis, which is crucial for protecting the body from oxidative stress and maintaining overall health. The food industry also exploits the antioxidant properties to prevent or delay the oxidation of other molecules during processing and storage. There are many classical methods for assessing antioxidant capacity/activity, which are based on mechanisms such as hydrogen atom transfer (HAT), single electron transfer (SET), electron transfer with proton conjugation (HAT/SET mixed mode assays) or the chelation of selected transition metal ions (e.g., Fe²⁺ or Cu¹⁺). The antioxidant capacity (AOxC) index value can be expressed in terms of standard AOs (e.g., Trolox or ascorbic acid) equivalents, enabling different products to be compared. However, there is currently no standardized method for measuring AOxC. Nanoparticle sensors offer a new approach to assessing antioxidant status and can be used to analyze environmental samples, plant extracts, foodstuffs, dietary supplements and clinical samples. This review summarizes the available information on nanoparticle sensors as tools for assessing antioxidant status. Particular attention has been paid to nanoparticles (with a size of less than 100 nm), including silver (AgNPs), gold (AuNPs), cerium oxide (CeONPs) and other metal oxide nanoparticles, as well as nanozymes. Nanozymes belong to an advanced class of nanomaterials that mimic natural enzymes due to their catalytic properties and constitute a novel signal transduction strategy in colorimetric and absorption sensors based on the localized surface plasmon resonance (LSPR) band. Other potential AOxC sensors include quantum dots (QDs, <10 nm), which are particularly useful for the sensitive detection of specific antioxidants (e.g., GSH, AA and baicalein) and can achieve very good limits of detection (LOD). QDs and metallic nanoparticles (MNPs) operate on different principles to evaluate AOxC. MNPs rely on optical changes resulting from LSPR, which are monitored as changes in color or absorbance during synthesis, growth or aggregation. QDs, on the other hand, primarily utilize changes in fluorescence. This review aims to demonstrate that, thanks to its simplicity, speed, small sample volumes and relatively inexpensive instrumentation, nanoparticle-based AOxC assessment is a useful alternative to classical approaches and can be tailored to the desired aim and analytes. Full article

Microbial electrolysis cells (MECs) are bioreactors that utilize electroactive microorganisms to catalyze the oxidation of organic substrates in wastewater, generating electron flow for hydrogen production. Despite the concept, a persistent performance gap exists where metabolically active anodic biofilms frequently fail to achieve expected current densities by the flow of electrons to produce hydrogen. This review examines the multiple causes that lead to the disconnect between robust biofilm development, electron transfer, and hydrogen production. Factors affecting biofilm generation (formation, substrate selection, thickness, conductivity, and heterogeneity) are discussed. Moreover, factors affecting electron transfer (electrode configuration, mass transfer constraints, key electroactive species, and metabolic pathways) are discussed. Also, substrate diffusion limitations, proton accumulation causing inhibitory pH gradients in stratified biofilms, elevated internal resistance, electron diversion to competing processes like hydrogenotrophic methanogenesis consuming H₂, and detrimental biofilm aging, impacting hydrogen production, are studied. The critical roles of electrode materials, reactor configuration, and biofilm electroactivity are analyzed, emphasizing advanced electrochemical (CV, EIS, LSV), imaging (CLSM, SEM, AFM), and omics (metagenomics, transcriptomics, proteomics) techniques essential for diagnosing bottlenecks. Strategies to enhance extracellular electron transfer (EET) (advanced nanomaterials, redox mediators, conductive polymers, bioaugmentation, and pulsed electrical operation) are evaluated for bridging this performance gap and improving energy recovery. The review presents an integrated framework connecting biofilm electroactivity, EET kinetics, and hydrogen evolution efficiency. It highlights that conventional biofilm metrics may not reflect actual electron flow. Combining electrochemical, microelectrode, and omics insights allows precise evaluation of EET efficiency and supports sustainable MEC optimization for enhanced hydrogen generation. Full article

Silver nanomaterials (Ag NMs) are widely used, including in consumer products, and they inevitably enter the environment, with the soil compartment acting as a major sink. However, most available toxicity data focus on the reference Ag NM300K and rely on standard tests, even though long(er)-term exposure tests are recognized as particularly important for assessing the risks to soil invertebrates. Hence, the aim of the present study was to investigate the toxicity of commercial Ag NPs (Ag-Sigma, NPs < 150 nm) to the soil ecotoxicology model Folsomia candida (Collembola). Effects were assessed based on the standard OECD reproduction test (28 days) and beyond, with exposure prolonged for a second generation (56 days). Results showed that, based on the standard test (50% reproduction effect concentration—EC50 = 988 mg Ag/kg soil), the commercial Ag NPs were less toxic than the reference Ag NM300K and the ionic form AgNO₃ (from literature). However, the toxicity dramatically increased (ca. 4 times) during the second-generation exposure (EC50(56d) = 234 mg Ag/kg soil), surpassing the toxicity of Ag NM300K. The decrease in adults’ size indicates that moulting might be affected. Overall, increased toxicity in prolonged exposure was not expected based on the available and standard test results, which highlights the importance of long(er)-term exposures to fully assess the risks of NMs to soil communities. Full article

Zinc oxide (ZnO) nanoparticles are widely used in cosmetics, coatings, and industrial formulations due to their UV-absorbing and antimicrobial properties; however, their increasing release into aquatic systems has raised concerns about potential ecological risks. This study evaluates the acute toxicity of pure and silver-doped ZnO (Ag-ZnO) nanoparticles using Artemia salina as a marine model organism. Nanoparticles were synthesized via a reflux-assisted method and characterized by UV–Vis spectroscopy, HRTEM, ED, FTIR, and EDX analyses, confirming a crystalline wurtzite structure, particle sizes of 10–30 nm, and successful incorporation of 5% Ag. Silver doping produced a slight blue shift in the absorption edge and minor lattice distortions, indicating modifications in the electronic structure. Toxicity assays revealed clear concentration- and time-dependent decreases in nauplii survival. Dose–response modeling showed LC₅₀ values of 358 ppm (24 h) and 64 ppm (48 h) for pure ZnO, whereas Ag-ZnO exhibited LC₅₀ values of 607 ppm (24 h) and 28 ppm (48 h). These results indicate that Ag doping does not enhance short-term toxicity but markedly increases toxicity after prolonged exposure. Overall, the findings highlight the need to consider both nanomaterial composition and exposure duration in ecotoxicological assessments and provide relevant data for evaluating the environmental impact of doped nanomaterials in marine systems. Full article

Accurate potentiometric sensing critically depends on the stability and reproducibility of the reference electrode potential. Conventional liquid-filled Ag/AgCl or calomel electrodes, though well-established, are poorly compatible with miniaturized, portable, or long-term in situ sensing devices due to electrolyte leakage, junction potential instability, and maintenance requirements. Recent advances in solid-state and membrane-based reference electrodes offer a promising alternative by eliminating the liquid junction while maintaining stable and well-defined potential. This review summarizes the advancements in polymer-based and composite reference membranes, focusing on material strategies, stabilization mechanisms, and integration approaches. Emphasis is placed on ionic-liquid-doped membranes, conducting polymers, lipophilic salts, and carbon nanomaterials as functional components enhancing interfacial stability and charge transfer. The performances of various architectures, solid-contact, liquid-junction-free, and quasi-reference systems, are compared in terms of potential drift, matrix resistance, biocompatibility, and manufacturability. Furthermore, recent developments in printed, microfluidic, and wearable potentiometric platforms demonstrate how reference membrane innovations enable reliable operation in compact, low-cost, and flexible analytical systems. The review outlines current trends, challenges, and future directions toward universal, miniaturized, and leak-free reference electrodes suitable for innovative sensing technologies. Full article

Background/Objectives: Flavonoids have been extensively investigated as reducing and stabilizing agents in the green synthesis of metallic nanoparticles. However, studies specifically employing pure naringin (NG) and naringenin (NGN) remain relatively scarce. Methods: In the present work, silver nanoparticles (AgNPs) were synthesized under controlled laboratory conditions using NG and NGN as bioreductants, and critical parameters governing nanoparticle formation were optimized. The synthesized AgNPs were comprehensively characterized using ultraviolet–visible (UV–Vis) spectroscopy, dynamic light scattering (DLS), scanning transmission electron microscopy (STEM), energy-dispersive X-ray spectroscopy (EDX), and Fourier-transform infrared spectroscopy (FTIR). Results: The characterization analyses confirmed the successful formation of predominantly spherical AgNPs with average particle sizes of 17 nm (AgNG) and 20.4 nm (AgNGN). DLS analysis indicated zeta potentials of approximately −30 mV and PDIs of 0.45 (AgNG) and 0.29 (AgNGN), consistent with stable colloidal dispersions. Biological evaluations revealed that both AgNP systems exhibited notable antioxidant and antimicrobial activities. Furthermore, cytogenetic assessment using the Allium cepa assay demonstrated concentration-dependent alterations in mitotic index and chromosomal integrity, indicating biological activity at cellular level. Conclusions: Collectively, these results underscore the potential of flavonoid-mediated synthesis as an eco-friendly and effective approach for generating stable, bioactive nanomaterials with promising biological applications. Full article

In the field of enhanced oil recovery in low-permeability reservoirs, the application of nanomaterials has attracted widespread attention. However, conventional nanomaterials exhibit issues such as large particle size and poor dispersion stability. This study selected SiO₂ nanoparticles with a particle size of 10 nm and combined them with 12 types of commonly used oilfield surfactants. After aging at 120 °C for 48 h, using dispersion stability and interfacial tension (IFT) as evaluation criteria, hexadecyltrimethylammonium bromide (CTAB) was ultimately identified as the optimal modifier. The structure and morphology of the SiO₂ particles were characterized in detail using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM). The system evaluated the dispersion stability of nanofluids before and after modification, as well as the interfacial properties (IFT reduced to the 10⁻¹ mN/m range) and wettability (oil-wet surfaces reversed to strongly water-wet, with contact angles decreasing to 30°) of nanofluids with different modification degrees. Considering economic factors, the modified nano-SiO₂ system with a ratio of 1:0.5 was selected. Microvisualization experiments revealed that the modified nanoscale system achieves residual oil displacement through three mechanisms: emulsification (reducing residual oil droplet size to enhance mobility), wetting reversal (lowering contact angle to weaken adhesion), and structural separation pressure (counteracting capillary forces to destabilize residual oil). Displacement experiments reveal that in rock cores with permeability ranging from 1 to 100 mD, the modified system exhibits a recovery rate trend that initially increases and then decreases. Nevertheless, it consistently enhances recovery rates, maintaining them above 12%, demonstrating strong application potential. Full article

Fractured lost circulation remains a major drilling challenge due to low compatibility between conventional plugging materials and fractures. By utilizing thermosetting resin emulsification and high-temperature crosslinking coalescence, this study developed a temperature-activated nanomaterial enhanced liquid–solid phase transition plugging emulsion. The system adapts to varying fracture apertures, forming plugging particles with a broad size distribution and high strength upon thermal activation. The structural characteristics, mechanical properties, and fracture-plugging performance of the plugging particles were systematically investigated. Results demonstrate that the optimized system, comprising 8 wt.% emulsifier, 0.16 wt.% dispersant, 0.4 wt.% crosslinker, 0.4 wt.% viscosifier, 70 wt.% distilled water, and 2 wt.% nano-silica (all percentages relative to epoxy resin content), can produce particles with a size of 1–5 mm at formation temperatures of 80–120 °C. After 16 h of thermal aging at 180 °C, the particles exhibited excellent thermal stability and compressive strength, with D(90) degradation rates of 3.07–5.41%, and mass loss of 0.63–3.40% under 60 MPa. The system exhibits excellent injectability and drilling fluid compatibility, forming rough-surfaced particles for stable bridging. Microscopic analysis confirmed full curing in 140–180 min. Notably, it sealed 1–5 mm fractures with 10 MPa pressure, enabling adaptive plugging for unknown fracture apertures. Full article

Background: Minimally invasive hyperthermia and regenerative therapies require materials that deliver precise, localized heat without compromising biocompatibility. Most conventional polymers are thermally insulating and challenging to control in vivo, motivating this review. Objectives: We aimed to (i) examine the use of thermally enhanced biopolymers in hyperthermia-based therapies, (ii) appraise evidence from clinical and preclinical studies, (iii) identify and classify principal applications in regenerative medicine. Methods: A PRISMA-guided systematic review (2020–2025) with predefined inclusion/exclusion criteria was conducted and complemented by a bibliometric analysis using VOSviewer for mapping and visualization. Results: Modifying biopolymers—via functionalization with photothermal or magnetic nanoagents (Au; Fe₂O₃/Fe₃O₄/CoFe₂O₄; CuS; Ag; MXenes, e.g., Nb₂C), crosslinking strategies, and hybrid formulations—significantly increased thermal conductivity, enabling localized hyperthermia and controlled drug release. In vitro and in vivo studies showed that europium-doped iron oxide nanoparticles embedded in chitosan generated heat efficiently while sparing healthy tissues, underscoring the need to balance biocompatibility and thermal performance. Hydrogel systems enriched with carbon nanomaterials (graphene, carbon nanotubes) and matrices such as GelMA, PNIPAM, hyaluronic acid, and PLA/PLGA demonstrated tissue compatibility and effective thermal behavior; graphene was compatible with neural tissue without inducing inflammation. Conclusions: Thermally conductive biopolymers show growing potential for oncology and regenerative medicine. The evidence supports further academic and interdisciplinary research to optimize safety, performance, and translational pathways. Full article

Nanotechnology offers powerful new tools to enhance food quality monitoring and safety assurance. In the food industry, nanoscale materials (e.g., metal, metal oxide, carbon, and polymeric nanomaterials) are being integrated into sensory systems to detect spoilage, contamination, and intentional food tampering with unprecedented sensitivity. Nanosensors can rapidly identify foodborne pathogens, toxins, and chemical changes that signal spoilage, overcoming the limitations of conventional assays that are often slow, costly, or require expert operation. These advances translate into improved food safety and extended shelf-life by allowing early intervention (for example, via antimicrobial nano-coatings) to prevent spoilage. This review provides a comprehensive overview of the types of nanomaterials used in food sensory applications and their mechanisms of action. We examine current applications in detecting food spoilage indicators and adulterants, as well as recent innovations in smart packaging and continuous freshness monitoring. The advantages of nanomaterials—including heightened analytical sensitivity, specificity, and the ability to combine sensing with active preservative functions—are highlighted alongside important toxicological and regulatory considerations. Overall, nanomaterials are driving the development of smarter food packaging and sensor systems that promise safer foods, reduced waste, and empowered consumers. However, realizing this potential will require addressing safety concerns and establishing clear regulations to ensure responsible deployment of nano-enabled food sensing technologies. Representative figures of merit include Au/AgNP melamine tests with LOD 0.04–0.07 mg L⁻¹ and minute-scale readout, a smartphone Au@carbon-QD assay with LOD 3.6 nM, Fe₃O₄/DPV detection of Sudan I at 0.001 µM (linear 0.01–20 µM), and a reusable Au–Fe₃O₄ piezo-electrochemical immunosensor for aflatoxin B1 with LOD 0.07 ng mL⁻¹ (≈15 × reuse), alongside freshness labels that track TVB-N/amine in near-real time and e-nose arrays distinguishing spoilage stages. Full article

Silver sulfide quantum dots (Ag₂S QDs) are promising nanomaterials for biomedical applications due to their near-infrared emission and biocompatibility. In this study, Ag₂S QDs were synthesized using bovine serum albumin (BSA) as a stabilizing and reducing agent to assess their potential in targeted photothermal therapy. The QDs showed an average size of 1.06 ± 0.38 nm by DLS and 4.42 nm by TEM. Conjugation to an anti-PSG1 monoclonal antibody was performed via EDC/Sulfo-NHS chemistry and confirmed by FTIR spectroscopy, a decrease in zeta potential, and a redshift in emission. The conjugate exhibited an average size of 22.82 ± 9.7 nm and a zeta potential of +85.7 mV, indicating high colloidal stability. Fluorescence studies showed that the conjugate emits at 590 nm when excited at 560 nm, whereas the BSA-Ag₂S QDs (non-conjugated) emit at 480 nm upon excitation at 400 nm, reflecting changes in optical properties due to conjugation. Thermal imaging under 808 nm laser irradiation revealed efficient photothermal conversion, with temperature increases up to 13.6 °C at 200 μg/mL and a conversion efficiency of 11.41 ± 0.04%. The conjugate was non-cytotoxic to fibroblasts but induced selective cytotoxicity in HeLa cells after laser exposure, with a selectivity index of 3.0. These findings suggest that Ag₂S-BSA QDs conjugated with anti-PSG1 represent promising candidates for further investigation in cancer nanotheranostics. Full article