Search Results (7,320)

Waste management presents a major environmental and public health challenge, creating an urgent need for strategies that convert discarded materials into higher-value products. Waste-derived nanoparticles (WDNPs) have gained increasing attention because they integrate waste valorization with the production of functional nanomaterials for environmental, biomedical, agricultural, packaging, sensing, catalytic and energy-related applications. This review critically evaluates WDNP synthesis from five major waste streams, including agricultural residues, animal-derived waste, plastic waste, electronic waste and industrial by-products. Across these categories, precursor composition strongly influences nanoparticle size, morphology, surface chemistry, stability and functional performance, making feedstock selection and processing conditions central to reproducible production. Evidence from recent studies indicates that WDNPs have broad functional potential across environmental remediation, biomedical delivery, antimicrobial systems, sustainable packaging, agriculture, energy storage and catalysis. However, translation beyond laboratory-scale studies remains limited by feedstock variability, limited reproducibility, complex purification requirements, potential toxicity, insufficient standardization and limited pilot-scale validation. By comparing synthesis approaches, application outcomes and translational barriers across waste categories, this review provides a critical overview of the opportunities and limitations of WDNPs and identifies the key requirements for their responsible development within a circular-economy framework. Full article

Lead (Pb²⁺) and cadmium (Cd²⁺) are among the most hazardous heavy metal pollutants in wastewater owing to their high toxicity, environmental persistence, and detrimental impacts on human health and aquatic ecosystems. In this study, a novel ternary magnetic composite, SnFe₂O₄/activated carbon/polypyrrole (SnFe₂O₄/AC/PPy), was effectively synthesized and tested as an effective adsorbent in the removal of Pb²⁺ and Cd²⁺ from aqueous water. The composite was prepared by depositing spinel SnFe₂O₄ nanoparticles on activated carbon, followed by in situ polymerization of polypyrrole to enhance surface functionality and adsorption affinity. The successful fabrication of the porous SnFe₂O₄/AC/PPy hybrid composite was confirmed through FTIR, XRD, SEM–EDS, BET, XPS, and VSM characterization. The composite demonstrated a relatively high surface area (352.3 m²/g) and adequate magnetic responsiveness (12.33 emu/g), ensuring facile magnetic separation following wastewater treatment. Batch adsorption experiments showed great removal efficiency of 95.02 and 92.48% for Pb²⁺ and Cd²⁺ ions, respectively, at optimum conditions. The adsorption equilibrium data followed the Langmuir isotherm model with maximum adsorption capacities of 187.07 mg/g for Pb²⁺ and 96.45 mg/g for Cd²⁺ ions, which were attributed to monolayer adsorption on homogenous active sites. The kinetic and isothermal model indicated that the adsorption process was controlled by the combination of physical and chemical interactions. Thermodynamic parameters showed negative Gibbs free energy and enthalpy changes (ΔH° = −49.74 kJ/mol for Pb²⁺ and −38.82 kJ/mol for Cd²⁺ ions), confirming the spontaneous and exothermic nature of adsorption. Furthermore, the increasingly negative ΔG° values at lower temperatures indicated that the adsorption was thermodynamically more favorable under cooler conditions. According to the regeneration studies, the composite maintained a high removal efficiency after five consecutive cycles. In general, SnFe₂O₄/AC/PPy composite has good potential as a stable, reusable, and high-performance adsorbent to treat heavy metal wastewater. Full article

Photosynthetic biogas upgrading (PBU) using microalgae is a promising biological approach for converting raw biogas into biomethane while recovering nutrients and fixing part of the biogenic CO₂ into algal biomass. Unlike conventional physicochemical technologies, which mainly separate CO₂ from CH₄, PBU can combine gas upgrading with wastewater or digestate treatment, nutrient recycling, and biomass production. This review assesses the current state of PBU technology, with particular emphasis on high-rate algal ponds, absorption columns, and closed photobioreactors. It examines the main operating parameters that control gas–liquid mass transfer, carbonate buffering, and photosynthetic activity, including the liquid-to-gas ratio, pH, alkalinity, temperature, light regime, light intensity, and gas retention time. Special attention is given to the combined effects of the L/G ratio, pH, and alkalinity, as these parameters strongly influence CO₂ absorption, CH₄ enrichment, and O₂ contamination of the upgraded gas. The use of wastewater or anaerobic digestate instead of synthetic growth media is identified as an important sustainability advantage, particularly at wastewater treatment plants with existing anaerobic digestion and nutrient-rich side streams. However, digestate use may also create operational challenges related to turbidity, ammonium inhibition, solids, and variable composition. Available studies indicate that PBU may reduce operating costs and greenhouse gas emissions under favorable conditions while creating additional value from algal biomass. Nevertheless, wider deployment is still limited by high land requirements, seasonal variability, O₂ contamination, biomass harvesting, and limited evidence from large-scale systems. Future development should therefore focus on improved oxygen management, more efficient reactor designs, nanoparticle-assisted enhancement of photosynthetic activity, better integration with wastewater treatment, and AI-supported monitoring and control to improve process stability and support scale-up. Full article

Natural Ophiocordyceps sinensis is a highly valued medicinal fungus known for its antitumor, immunomodulatory, and antiviral properties. Due to extensive overharvesting in Asia, cultivated alternatives have become increasingly important. This study aimed to evaluate the biological activity and chemical composition of extracts obtained from cultivated Ophiocordyceps sinensis grown using different rice substrates. Methanolic extracts were prepared from solid-state cultivated Ophiocordyceps sinensis grown on Oryza sativa var. indica and Oryza sativa var. japonica. Antioxidant activity was determined using the DPPH assay, while proteolytic activity was evaluated with the azocasein substrate. Chemical characterization of major compounds was performed using ¹D and ²D NMR spectroscopy, together with IR spectroscopy. UV/Vis spectrophotometry was employed to confirm the formation of silver nanoparticles in AgNO₃ solution. Antimicrobial activity was tested against bacterial strains, including Escherichia coli and Staphylococcus aureus. All prepared methanolic extracts exhibited measurable antioxidant and proteolytic activities. The dominant identified compounds were Z-oleic acid, linoleic acid, and D-mannitol. Selected extracts successfully induced the formation of silver nanoparticles. The highest antimicrobial activity against Escherichia coli was observed for sample 1OS, reaching a mean % RIZD value of 129.32 ± 0.58%. Full article

Gold nanoparticles (AuNPs) have emerged as versatile antiviral nanoplatforms because their size, morphology, plasmonic properties, and surface chemistry can be precisely engineered. In this review, we summarize the core design principles of antiviral AuNPs from a structure–function–mechanism perspective. We first outline representative synthetic and interface-programming routes for AuNP preparation, including citrate reduction, Brust–Schiffrin synthesis, seed-mediated growth, green synthesis, direct thiol-conjugation, and mixed-ligand shell strategies, emphasizing how these approaches define particle size, morphology, surface accessibility, interfacial composition, and downstream biofunctionalization potential. We then discuss major surface engineering strategies, including polyethylene glycol, nucleic acids, antibodies and nanobodies, peptides, glycans, antiviral drugs, and biomimetic coatings, with particular attention to how ligand density, orientation, flexibility, and interfacial stability determine biological performance. Next, we examine how functionalized AuNPs inhibit different stages of the viral life cycle, including viral attachment and entry, intracellular replication, assembly and egress, photothermal inactivation, and immune modulation or vaccine delivery. Finally, we highlight current challenges, including incomplete structure–activity relationships, dynamic nano–bio interactions under physiological conditions, limited standardization across studies, and translational barriers related to safety, reproducibility, and scale-up. This review provides a conceptual framework for the rational development of next-generation AuNP-based antiviral nanotherapeutics. Full article

Traditional mineral drugs represent an underexploited reservoir of natural antitumor agents; however, their clinical translation has historically been hindered by poor bioavailability, non-specific biodistribution, and dose-limiting toxicity. This review comprehensively examines the pharmacological mechanisms and modern formulation strategies driving the renaissance of mineral-based oncology therapeutics. We highlight how mineral drugs exert potent anticancer effects through interconnected pathways, including regulated cell death (e.g., apoptosis, ferroptosis), cell-cycle arrest, and immunomodulation. Crucially, we evaluate recent advances in drug delivery systems, such as liposomes, polymeric nanoparticles, inorganic frameworks, and stimuli-responsive (e.g., pH, redox, enzyme) release systems that successfully overcome traditional pharmacological barriers. These bioengineering strategies not only improve solubility and tumor targeting but also significantly widen the therapeutic window, as evidenced by enhanced tumor suppression and reduced systemic toxicity in preclinical models. Despite this progress, challenges regarding in vivo chemical transformations and tumor heterogeneity remain. Ultimately, we propose a closed-loop “Composition–Mechanism–Delivery” design paradigm to guide future research, facilitating the translation of ethnopharmacological heritage into precision mineral-based therapeutics. Full article

We report a low-temperature plasma–liquid synthesis of crystalline β-Ga₂O₃ nanoparticles directly from aqueous solution. Pulsed discharge plasma bubbles generate reactive species that drive in situ dehydration and crystallization, bypassing the high-temperature calcination required by conventional methods. By varying the carrier gas, we tune morphology from uniform nanorice structures (He, Ar, and N₂) to amorphous microspheres (O₂ and air), revealing how plasma composition governs interfacial hydroxyl radical chemistry and growth kinetics. This approach demonstrates that localized plasma heating and reactive-species flux can achieve phase-selective oxide crystallization under ambient conditions, establishing plasma bubble reactors as a broadly applicable, low-temperature route for direct aqueous synthesis of crystalline wide-bandgap oxides that bridge solution chemistry and plasma nanomaterials design. Full article

Nanobubbles have attracted increasing interest in food systems because they can modify gas dispersion, interfacial transport, washing performance, preservation processes, and the structures of dispersed matrices. However, their behavior cannot be interpreted based on bubble size alone. Proteins, polysaccharides, lipids, salts, colloidal particles, gas composition, and processing conditions can alter interfacial adsorption, gas transfer, bubble persistence, and matrix organization in food systems. This review examines the physicochemical mechanisms proposed to explain nanobubble persistence and functionality, with an emphasis on surface charge, interfacial adsorption, gas supersaturation, confinement, and interactions with food biopolymers. A central distinction is made between passive nanobubble-containing systems and externally activated systems involving hydrodynamic cavitation, ultrasound, plasma, pressure fluctuations, and reactive gases. Under passive conditions, nanobubbles mainly act as gas–liquid interfaces that influence local transport and adsorption. In activated systems, microbial inactivation, reactive oxygen species formation, and apparent mass-transfer enhancement often arise from external energy input, gas chemistry, turbulence, and transient supersaturation rather than from nanobubbles alone. Interfacial stability is used here as an organizing concept to connect nanobubble persistence, food-matrix interactions, generation methods, characterization limitations, and interpretation of reported technological effects. Current methods, such as dynamic light scattering and nanoparticle tracking analysis, provide useful size and concentration estimates but cannot unambiguously distinguish nanobubbles from protein aggregates, fat droplets, micelles, polysaccharide assemblies, and other colloidal structures in complex matrices. Therefore, reliable interpretation requires complementary methods, appropriate controls, and standardized reporting of gas composition, generation method, energy input, matrix properties, and processing conditions. Thus, nanobubble-containing technologies show promise for food processing; however, their value depends on the separation of nanoscale interfacial effects from concurrent hydrodynamic, chemical, and matrix-dependent phenomena. Full article

To address the application bottlenecks of organic phase change materials characterized by low thermal conductivity and susceptibility to liquid leakage, this study utilized natural poplar wood as a raw material to construct a three-dimensional carbon/silver heterogeneous porous skeleton via delignification, gradient carbonization, and in situ electroless silver plating. Polyethylene glycol (PEG) was then vacuum-encapsulated within this structure to prepare form-stable composite phase change materials (CPCMs). The regulatory effects of carbonization temperature and metal interface modification on the microscopic morphology and thermophysical properties of the materials were systematically investigated. The results indicate that the skeleton carbonized at 800 °C achieves an optimal balance between pore distribution and skeleton rigidity, ensuring the uniform conformal growth of silver nanoparticles and endowing the material with excellent anti-leakage performance. The thermal conductivity of the optimal sample reaches as high as 0.683 W/(m·K), with the melting latent heat maintained at 133.9 J/g, while also demonstrating an agile and stable photothermal conversion response. Non-equilibrium molecular dynamics (NEMD) simulations further confirm that the silver nanoparticle modification layer smooths the phonon vibration frequency mismatch between the carbon substrate and organic segments, significantly reducing the interfacial thermal resistance. This research provides an important reference for the structural design and microscopic heat transfer mechanism analysis of high-performance phase change energy storage materials. Full article

This work presents an enhanced photomechanical optical sensor inspired by our previously reported bio-inspired uncooled infrared detector. Performance improvement is achieved by strengthening the interfacial bond between the photothermal dendrite—polydopamine nanoparticle (PDA NP)/polydimethylsiloxane (PDMS) composite—and the piezoresistive laser-induced nanocarbon film, with a flexible PDMS substrate that provides both thermal insulation and mechanical stability. The resulting sensor exhibits a responsivity of 51.6 W⁻¹ under 808 nm irradiation, an order-of-magnitude enhancement over the unmodified device. Wavelength-dependent characterization (455–1550 nm) shows responsivity decreasing from 93.1 W⁻¹ at 455 nm to 14.4 W⁻¹ at 1550 nm, with response times on the order of seconds across this range. Extending this trend into the longer-wavelength region of blackbody radiation, the mechanism transitions to a predominantly bolometric mode. The device also demonstrates stable detection of several hundred microwatts and robust durability at 455 nm. These results validate interface engineering strategy as a viable pathway toward high-performance uncooled optical detection, advancing bio-inspired detectors from functional mimicry toward an application-ready platform. These findings confirm PDA NPs as effective photothermal converters primarily at shorter wavelengths, while the wavelength-dependent response suggests future tailoring of spectral sensitivity using long-wavelength-absorbing materials. Full article

This study reports the preparation of a nanocomposite using a black cumin surface as a carbon framework on which zinc oxide-doped manganese ferrite nanoparticles were deposited and grown. A simple precipitation method was used to prepare the nanocomposite. The resulting composite was characterized using various characterization analyses such as FTIR, XRD, EDX, SEM, TEM, and TGA. The composite surface was highly conformed with functional groups, and the nanocomposite was formed due to electrostatic and non-electrostatic interactions between the carbon framework and the nanoparticles. X-ray analysis revealed a crystalline structure with crystal sizes up to 45 nm. Microscopic images revealed the surface morphology, confirming the irregular distribution of particles within the composite. The resulting composite material was used for adsorption application. The composite material was tested for the removal of Congo red dye from water. It was found that under optimal conditions, a dose of 2 g per liter of absorbent removed nearly 100% of dye from a 10 mL volume of 10 mg per liter Congo red solution within 90 min and 7 pH. A monolayer adsorption was confirmed by the isotherm analysis. The monolayer adsorption capacity for the present study was ~13.0 mg per gram. The adsorption kinetics suggested the fitting of pseudo-second order. Based on the findings, it was concluded that the chemical mechanism was responsible for the present adsorption process. The regeneration study demonstrates the stability of current adsorbent up to two cycles only. This nanocomposite is the first of its kind which promotes the creation of nanocomposites in the future by using natural materials and reduces the dependency on activated carbon. Full article

This study investigates the potential of xylan acetylated using imidazolium-based ionic liquids, particularly 1-ethyl-3-methylimidazolium acetate ([Emim]Ac), as a functional matrix for ZnO and CuO nanoparticles (ZnO NPs and CuO NPs) in composite coatings for food packaging paper. A single coating layer (approximately 5 g/m²) was applied on both sides of the paper samples to improve barrier properties against water, oils, fats, and microbial contamination. The obtained results show that the combination of acetylated xylan with ZnO and CuO nanoparticles improved surface hydrophobicity, with contact angle values reaching 83° and 97°, respectively. The coatings exhibited antibacterial activity against Bacillus sp., as well as a reduction in fungal development of Penicillium spp., as evidenced by the observed inhibition of conidia sporulation. These findings indicate that ionic liquid-assisted acetylation of xylan using [Emim]Ac is an effective route for chemical modification of hemicelluloses. The developed xylan-based coatings demonstrate promising functional properties for potential application in sustainable food packaging materials, within the scope of the performed experiments. Full article

Heterogeneous hydrogels capable of complex, programmable deformation are highly desirable for soft actuators, yet general strategies that simultaneously impart structural anisotropy, rapid responsiveness, and mechanical robustness remain limited. Here, a gradient anisotropic natural rubber-poly(N-isopropylacrylamide) (NR-PNIPAM) composite hydrogel is developed through a simple one-pot polymerization strategy by coupling pH-regulated colloidal stability with gravity-directed redistribution of natural rubber latex particles. Under an optimized pH window, NR nanoparticles gradually migrate during gelation and are fixed as a continuous gradient within the PNIPAM network, generating built-in structural asymmetry for nonuniform deformation. Meanwhile, NR nanoparticles act as soft reinforcing domains to improve mechanical strength, while water-soluble graphene nanosheets provide efficient photothermal conversion for remotely-controlled near-infrared (NIR)-responsive actuation. Benefiting from this synergistic design, the hydrogel exhibits programmable bending and localized folding with high actuation rates of 129° s⁻¹ and 46° s⁻¹, respectively, along with a tensile strength of 0.32 MPa and an active lifting capability exceeding 70 times its own weight. The material further enables biomimetic gripping and lifting under NIR stimulation. This work establishes a general route to robust gradient hydrogels by integrating colloidal regulation, structural anisotropy, and photothermal actuation, offering a versatile platform for high-performance soft intelligent systems. Full article

The development of sustainable electrocatalysts for clean energy by modifying biomass-derived activated carbon with nitrogen and transition metals is presented. Activated carbon (AWC) material was obtained using alder wood char as a precursor, while nitrogen and cobalt or copper nanoparticles were incorporated with the aim of creating efficient materials for hydrazine oxidation (HzOR) and direct hydrazine–hydrogen peroxide fuel cells (DHHPFC, N₂H₄–H₂O₂). The composition, structure, and surface morphology of the created materials were examined using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), and inductively coupled plasma optical emission spectroscopy (ICP-OES). The activity of the AWC, AWC–Co–N, and AWC–Cu–N catalysts for HzOR was investigated using cyclic voltammetry (CV) and linear sweep voltammetry (LSV). N₂H₄–H₂O₂ fuel-cell tests were performed by applying the catalysts as both the anode and cathode. It was found that all materials retained a hierarchical porous carbon framework, while metal incorporation altered surface compactness. Cobalt doping produced well-dispersed Co nanoparticles and abundant Co–N–C coordination sites, whereas Cu introduction resulted in moderately compact structures with uniformly distributed Cu-based nanoparticles. Electrochemical measurements demonstrated that both metal dopants enhanced HzOR activity, with the catalytic performance following the order of AWC–Co–N > AWC–Cu–N > AWC. Fuel-cell testing further confirmed this trend: AWC–Co–N achieved the highest maximum power density (30.4 mW cm⁻²), outperforming AWC–Cu–N (17.7 mW cm⁻²). These results identify AWC–Co–N as a highly effective bifunctional electrocatalyst for DHHPFCs. Full article

Background: Persistent intraradicular infection and biofilm survival remain major challenges in endodontic treatment, particularly because residual microorganisms may remain within dentinal tubules despite chemomechanical preparation. The antimicrobial efficacy of sealers may be insufficient against resistant bacteria. This study evaluated the effect of incorporating red and black iron oxide nanoparticles into BioRoot RCS on its antimicrobial activity and cytocompatibility. Methods: BioRoot RCS was modified with red or black iron oxide nanoparticles at 0.5 wt% and 2.0 wt%, generating 5 groups: unmodified sealer, 0.5% red, 2.0% red, 0.5% black, and 2.0% black. Surface morphology was analyzed using scanning electron microscopy, while elemental composition was determined by energy-dispersive X-ray spectroscopy. Antibacterial activity against Enterococcus faecalis and Fusobacterium nucleatum was assessed using a direct contact test, antibiofilm activity by colony-forming unit reduction on infected dentin discs, and cytocompatibility using human gingival fibroblasts and the AlamarBlue assay. Results: Iron was detected in the modified formulations, and elemental mapping showed homogenous distribution of calcium and iron. The 2.0% formulations showed significantly higher antibacterial and antibiofilm effects than the corresponding 0.5% groups (p < 0.05), with 2.0% black showing the lowest bacterial counts. Cytocompatibility differed at 1 and 3 days but not at 7 days, and all groups remained close to the control level with no significant difference (p > 0.05). Conclusions: Within the limitations of this in vitro study, experimental modification of BioRoot RCS with iron oxide nanoparticles, particularly at 2.0 wt%, improved the antimicrobial and antibiofilm efficacy of BioRoot RCS while maintaining acceptable cytocompatibility. However, physicochemical and handling properties must be evaluated before the clinical relevance of this modification can be determined. Full article