Ergonomic and fully 3D-printed, activated, and modified electrochemical set-up for electroanalytical paracetamol detection.

This study evaluates the reducing potential of leaf extracts from the endemic species Abies nordmanniana subsp. equi-trojeni for the green synthesis of silver particles. The synthesis involved reacting a 1 mM silver nitrate (AgNO₃) solution with the plant extract at room temperature. We characterized both the reaction products and the supernatant using FTIR, UV-Vis, and SEM techniques. Our data confirm that phenolic compounds within the extract were actively consumed during the reduction of Ag⁺ ions. Interestingly, SEM analysis revealed that the synthesized particles exhibited micrometer-scale dimensions rather than the expected nanoscale dispersion. We attribute this micro-structure formation to the high reducing power and concentration of the extract, which likely drove rapid nucleation followed by immediate agglomeration. These findings confirm the strong reductive capacity of Abies nordmanniana subsp. equi-trojeni and suggest that future protocol optimization—particularly regarding pH and concentration control—is necessary to fine-tune particle size from the micro- to the nanoscale.

The growing threat of antimicrobial resistance (AMR) demands novel therapeutic strategies. This research explores a plant-based 'green' synthesis route for producing silver particles, employing an aqueous extract from the endemic Turkish plant Sideritis trojana Bornm. The process aimed to provide a sustainable alternative to conventional chemical methods. The resulting particles were subjected to a suite of characterization techniques, including Fourier-Transform Infrared Spectroscopy (FTIR), UV-Vis Spectroscopy, and Scanning Electron Microscopy (SEM). Spectroscopic analysis by FTIR suggested the involvement of the extract's phenolic constituents in both the reduction of silver ions and the stabilization of the final product. While UV-Vis analysis confirmed a successful reduction reaction, microscopic evaluation via SEM unexpectedly revealed the formation of aggregated structures on the micrometer scale, not nanoparticles. This outcome is hypothesized to result from a highly concentrated extract, which likely induced rapid, uncontrolled particle growth and agglomeration. The study confirms the bioreductive potential of S. trojana extract but underscores the critical need for process optimization to control particle dimensions for potential future applications.

In this work, we synthesized antibacterial core-shell structured magnetic nanoparticles with silver particles as the core and nickel-ferrite or cobalt-ferrite crystallites as the shell using solvothermal method. The prepared ferromagnetic amine-functionalized Ag/NiFe2O4 and Ag/CoFe2O4 particles had a saturation magnetization (Ms) of 40 emu/g and 37 emu/g, respectively, and were therefore easily separated from aqueous media by magnetic field, thus making them excellent magnetic adsorbents. The produced core-shell particles had mean diameters of 276 ± 70nm (Ag/CoFe2O4) and 337 ± 109nm (Ag/NiFe2O4). Due to their silver content, these particles showed outstanding antibacterial activity against Gram-positive (Micrococcus luteus) and Gram-negative (Escherichia coli) bacteria, which was confirmed by bacteriological studies. For E. coli, a nanoparticle concentration of less than 0.5mg/mL was sufficient to inhibit growth on solid surfaces, whereas for M. luteus a concentration of 3mg/mL was effective. This difference in antibacterial efficacy can be explained by differences in the cell wall structure of Gram-negative and Gram-positive bacteria. In addition to being effective in killing bacteria, both types of Ag-containing magnetic nanoparticles also exhibited excellent adsorption capacity, removing 100% of microorganisms from the tested solution. In liquid-phase assays, complete antibacterial and adsorptive efficacy was achieved at 1.0mg/mL for E. coli with Ag/CoFe₂O₄, while Ag/NiFe₂O₄ reached full efficiency at concentrations as low as 0.1mg/mL; for M. luteus, both 1.0 and 3.0mg/mL proved fully effective. Time-kill kinetic tests further confirmed the rapid action of the nanoparticles, with total bacterial elimination occurring within 10min. This rapid and high removal efficiency is likely attributed to the silver content and positive surface charge of the magnetic particles, which facilitates electrostatic interactions with the negatively charged bacterial membranes. Given their strong antibacterial and adsorption performance demonstrated in our experiments, these nanoparticles are highly promising candidates for water treatment applications in the future.

(1) Background: The replacement of petroleum-based plastics with sustainable biopolymer films is crucial for global food preservation. Biopolymers like zein and pectin offer biodegradable and compostable alternatives but often require functionalization. This study develops and characterizes a novel antioxidant film by incorporating silver microparticles (AgMp) derived from the valorization of an agricultural waste product: pecan nutshell extract. (2) Methods: AgMp were synthesized via green reduction method using the extract. These bioactive microparticles were subsequently incorporated into a zein/pectin polymeric solution using the solvent-casting technique. The particles and the active films were characterized using FTIR, SEM, and antioxidant assays (ABTS, DPPH, and FRAP). (3) Results: The extract and AgMp exhibited a potent antioxidant activity (100% inhibition for ABTS/DPPH). SEM analysis confirmed the scale of 0.545–1.033 µm, classifying the material as microparticles. The final films retained a dose-dependent antioxidant activity (66.78% for ABTS and 53.67% for DPPH). (4) Conclusions: This work validates that pecan nutshell extract as an effective green reducing and capping agent. The resulting film possesses significant antioxidant activity, offering a promising alternative for active food packaging applications, such as bioactive pads or inserts.

The intricate interplay between complex permittivity and permeability constitutes the cornerstone of electromagnetic (EM) applications, enabling precise customization for various uses. This study employed silver-epoxy nano-composites to exemplify a conductor-insulator composite, leveraging silver’s exceptional attributes, such as high conductivity and low reactivity. The determination of complex permittivity and permeability was conducted via the transmission/reflection method. At lower concentrations of dispersed silver particles, these nanoparticles within the epoxy resin act as modest dipoles, augmenting permittivity. This regime aligns closely with the effective medium theory (EMT) and comprises the focus of much research. However, nearing the percolation threshold, a percolation effect emerges, drastically accelerating enhancement rates beyond the predictions of EMT. Simultaneously, long-wavelength electromagnetic waves induce diamagnetic currents within loops formed by metal grains. This diamagnetic effect intensifies with increasing volume fraction, leading to a reduction in permeability. Here we report the first simultaneous extraction of complex permittivity and permeability for a metal–polymer system inside the microwave percolation window (8.2 ~ 12.4 GHz). We observe a record-high :{epsilon:}^{prime}approx496 co-existing with a record-low :{mu:}^{prime}approx0.31, and we show that both quantities obey 2D percolation scaling. The results constitute the first experimental verification of the Bowman–Stroud diamagnetic-loop model at GHz frequencies.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-27457-0.

Plasmonic silver particles reduced by contact-electro-catalysis with acoustic-solid interaction mechanism for enhancing SERS detection

ABSTRACT The efficient reovery of silver from industrial waste is crucial for resource sustainability and environmental protection. In this study, a novel adsorbent, 4,4’-(((oxalylbis(azanediyl))bis(carbonothioyl))bis(azanediyl))bis(3-hydroxy naphthalene-1-sulphonic acid)-impregnated Amberlite A×D7(TUD@AXD7), was synthesised and characterised using SEM, BET, FTIR, 1H NMR, 13C NMR, and GC-MS. The material exhibited a substantial surface area of 238.54 m2/g, contributing to its impressive Ag(I) adsorption capacity of 345.5 mg/g at pH 5.0. Adsorption equilibrium was best described by the Langmuir isotherm model (R2 > 0.99), indicating monolayer adsorption. Kinetic analysis revealed that the process followed a pseudo-second-order model (k₂ = 0.0011 g mg−1 min−1), suggesting a chemisorption mechanism. The thermodynamic evaluation confirmed that adsorption was both spontaneous and endothermic, with ΔG° = −13.36 kJ/mol, ΔH° = 1120.1 kJ/mol, and ΔS° = 48.574 J/mol·K. The highest adsorption efficiency was achieved under optimised conditions, including pH 5.0, a contact time of 30 minutes, and an adsorbent dose of 80 mg at ambient temperature. The adsorbed silver was desorbed as AgNO₃ and subsequently utilised for the green synthesis of silver nanoparticles (AgNPs) using trisodium citrate as a reducing agent. The synthesised AgNPs were thoroughly characterised to assess their morphology, composition, and structural properties. Additionally, the TUD compound exhibited promising antioxidant (H₂O₂ scavenging) and antifungal activity, broadening its potential applications. The adsorbent demonstrated excellent stability and reusability over multiple adsorption-desorption cycles without significant efficiency loss. These findings highlight TUD@AXD7 as a cost-effective and sustainable material for silver recovery and contribute to the field of environmental science and materials chemistry by providing a novel method for silver recovery and its applications in nanotechnology and environmental remediation.

Nanotechnology, a rapidly evolving discipline, shows remarkable promises for revolutionizing a wide range of industries, offering innovative solutions to long-lasting challenges. In the research Within the food sector, packaging and preservation, the application of nanoparticles (NPs) represents a significant breakthrough, enhancing product freshness, safety and reducing waste. Widely studied NPs such as copper oxide (CuO), silver (Ag), magnesium oxide (MgO), titanium dioxide (TiO2), silicon dioxide (SiO2), zinc oxide (ZnO), carbon dots, graphene, chitosan and mesoporous particles have demonstrated remarkable potential in extending product’s freshness and reduce safety risks by inhibiting microbial growth and lowering spoilage in tomato, broccoli, spinach and other green vegetables. This review highlights the utilization of NPs, including Ag, ZnO, TiO2, SiO2, nanoclay and nanochitosan as well as nanoencapsulation techniques, in food systems. Furthermore, it explores how nanotechnology can revolutionize food packaging and preservation by enabling more effective, efficient and environmentally sustainable practices, ultimately contributing to a greener and more secure global food supply chain.

The influence of disorder in the spatial arrangement of identical, homogeneous spherical particles of an infinite two-dimensional (2D) array on the energy density spectra of the electric and magnetic fields on their surfaces under normal incidence of a plane electromagnetic wave is studied. The consideration is based on a semi-analytical statistical method (SASM) developed by us. Radial distribution functions based on the hard-disk model are used to simulate particle arrangements in arrays. We wrote a formula for this function describing the perfect azimuthally averaged lattice and analyzed in detail the energy densities for different deviations of particle centers from the nodes of the perfect lattice. The calculation results for a partially ordered array and imperfect and perfect lattices of silver (Ag), crystalline silicon (c-Si), and titanium oxide (TiO2) particles with sizes of 50 and 300nm are presented in the wavelength range of 0.3-1.1µm for a host medium with a refractive index close to that of water. They demonstrate the contribution of the disorder effect to the optical response of the system and allow finding the optimal characteristics of lattice-induced resonances for energy densities on the particle surface. Such data are necessary for solving problems of increasing the efficiency of converting light energy absorbed by the system into other types of energy. The spectra of energy densities obtained under the SASM are in excellent agreement with the data of the numerical finite element method (FEM). To complete the picture, the near-field data are accompanied by far-field data for the incoherent component of the light.

The aim of the study was to determine how to produce green silver nanoparticles (AgNPs) from silver precursors in an economical and environmentally responsible manner. In order to achieve the green synthesis of AgNPs using the aqueous extract of turmeric powder, plant biomaterials were employed as a capping and reducing agent. Energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) and ultraviolet-visible spectrophotometer was used to analyze AgNPs. The UV-vis spectrum's highest absorption was measured at 431 nm. SEM showed the presence of several silver particles at the nanoscale, which indicates the success of the AgNPs biosynthesis. Furthermore, X-ray diffraction showed that the AgNPs are crystalline and face-centered cubic (FCC) in nature, while FT-IR spectral analysis identified the number of functional biological groups that serve as capping or stabilizing agents in the stabilization of nanoparticles. The presence of the silver element in the produced AgNPs was further confirmed by EDX. The green-produced AgNPs exhibit effective antibacterial activity against urinary tract infection-causing isolates of bacteria. The concentration of 8 mM showed the highest rate of inhibition zone against Escherichia coli, Staphylococcus spp., Pseudomonas aeruginosa and Klebsiella pneumoniae with inhibition zone value of 19 mm, 17.4 mm, 12.6 mm and 10.7 mm respectively. These results imply that isolates of E. coli are the main target of AgNPs' inhibitory action. Furthermore, at 75 µg/mL, AgNPs show efficient antioxidant activity (IC50), which is greater than that of the common antioxidant Trolox, which reduces the ABTS radical at 25 µg/mL.

Metal-coated mesoporous PSi (mesoPSi) opens up disruptive perspectives for biosensing, which is primarily enabled by surface-enhanced Raman scattering (SERS). Although the unique performance of SERS-active substrates based on metal-coated mesoPSi has already been praised, influence of defects in silicon wafer on its morphology has not been revealed. Defects lead to formation of spiral regions in mesoPSi with varying porosity, which affects SERS activity of the overlying metallic nanostructures. It limits the reliability of SERS analysis. Here, we investigate repeatability of morphology and SERS activity of silver particles on mesoPSi as a function of defects in parent silicon, which are induced by irregular dopant levels. We propose an original corrosion approach that has not yet been applied to control the morphology of silicon nanostructures in general and mesoPSi in particular. By replacing silicon nanocrystallites with sacrificial copper nanoparticles, we were able to eliminate the surface irreproducibility of mesoPSi. The copper-corrosion-modified porous silicon surface was shown to be a suitable substrate for reliable SERS-active substrates. In more detail, SERS-active substrate based on mesoPSi without a defective surface layer allowed for a more than 40% increase in the SERS-active surface area with a signal deviation of only 10 % compared to that with a defective layer.

The present study focused on the antibacterial activity, mechanism and application of Pseudoduganella armeniaca ZMN − 3 extracellular polysaccharide nano silver. Extracellular polysaccharide nano silver was prepared by chemical synthesis and characterized by UV - Vis spectroscopy, Fourier transform infrared spectroscopy, X - ray diffraction, X - ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy. The antibacterial effects of extracellular polysaccharide nano silver on two common pathogens were investigated by agar well diffusion method and broth dilution method. The results showed that extracellular polysaccharide nano silver had significant inhibitory effects on Escherichia coli and Staphylococcus aureus. In addition, by SEM and TEM observation, the conductivity, the leakage of nucleic acids and proteins, the release of reducing sugars, the ATP content, and the alkaline phosphatase level were also measured. The study results indicated that extracellular polysaccharide nano silver could cause the leakage of large biomolecules such as nucleic acids and proteins, reduce the release of sugars, increase ATP content, and lead to the leakage of alkaline phosphatase, ultimately resulting in bacterial death. Finally, the application of extracellular polysaccharide nano silver in antibacterial coating was studied. Antibacterial coating achieved an impressive inhibition rate of 99% against both Escherichia coli and Staphylococcus aureus and could effectively resist bacterial adhesion within 7 days. This study provides a theoretical basis for the potential application of Pseudoduganella armeniaca ZMN − 3 extracellular polysaccharide nano silver in the antibacterial field.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12896-025-01052-7.

ObjectiveTo investigate the antibacterial effects of nanosilver (nAg)-polyethylene glycol (PEG) chitosan (CTS)-polyvinyl alcohol (PVA) dressing on post-cesarean section (CS) incisions and its impact on breastfeeding rates.MethodsInitially, nAg-PEG-CTS-PVA, as an antibacterial dressing, was prepared using the PEG reduction method, and the morphology of nAg-PEG was observed using transmission electron microscopy. The water absorption capacity of the nAg-PEG-CTS-PVA sponge was measured, and its pore structure was observed using scanning electron microscopy. Furthermore, the in vitro release of silver particles and antibacterial effects were evaluated. Subsequently, 94 CS patients were divided into two groups: the control group (conventional antimicrobial treatment) and the nAg group (nAg antibacterial dressing), with 47 cases in each group. The outcome measures assessed included the incidence of postoperative wound infection, wound healing time, frequency of dressing changes, maternal pain intensity before and after intervention (evaluated using the visual analog scale (VAS)), LATCH breastfeeding assessment tool scores, and the exclusive breastfeeding rate within six months.ResultsnAg particles were uniformly dispersed in PEG, with a particle size ranging from 13 to 21 nm, predominantly spherical in shape. The CTS-PVA sponge containing nAg-PEG exhibited optimal water absorption when PVA-AH-26 accounted for 70%, displaying uniform pore distribution with higher density and pore sizes between 0.3 and 1.1 mm. The cumulative release rate reached 70% on the 8th day, and by the 28th-30th days, the cumulative release rate was 96%. The sponge demonstrated excellent bactericidal effects against Staphylococcus aureus, Gram-negative bacilli, coagulase-negative Staphylococcus, Enterococcus, and Escherichia coli. In comparison with the control group, the nAg group showed shorter wound healing time, lower wound dressing change frequency, lower visual analog scale scores, and a higher rate of exclusive breastfeeding (P < 0.05).ConclusionThese findings indicated that the antibacterial dressing containing nAg-PEG-CTS-PVA sponge had effective antimicrobial, analgesic, and wound healing-promoting properties, leading to a higher rate of exclusive breastfeeding after CS.

Tailored copolymers for soft templating of silver particles with enhanced antibacterial properties

Argyria, characterized by irreversible bluish-gray skin pigmentation due to silver accumulation, presents significant cosmetic concerns. Scanning transmission electron microscopy (STEM) combined with energy-dispersive X-ray spectroscopy (EDS) allows for precise identification of silver particles in tissue; however, standard specimen preparation protocols are labor-intensive. This study evaluates the feasibility, diagnostic utility, and limitations of a simplified STEM-EDS method using conventionally prepared transmission electron microscopy (TEM) specimens. A 72-year-old man with a two-year history of ingesting silver-ionized water three times daily presented with diffuse blue-brown pigmentation of the facial skin and nails. Based on clinical suspicion of systemic argyria, skin biopsy samples were analyzed using STEM-EDS on ultrathin sections prepared via standard TEM protocols. Granules approximately 200-400 nm in diameter exhibited distinct EDS emission peaks for silver and selenium. Elemental line scans revealed silver as the primary component, and areal mapping confirmed the co-localization of silver and selenium within the same granules. This case highlights the diagnostic utility of STEM-EDS in confirming silver deposition in suspected systemic argyria, even when using standard TEM-prepared samples. The streamlined approach eliminates the need for additional specimen processing while maintaining analytical integrity.

The printed electronics sector is experiencing significant growth driven by societal expectations. The use of cellulosic substrates is an excellent strategy that offers interesting research prospects, but also sets challenges in terms of management and recycling of these new wastes to avoid their accumulation. This work investigates the recycling ability of paper-based printed electronics (a simple RFID antenna printed on paper), containing silver particles in the functional ink, using processes already applied in conventional paper and board recycling lines. These operations, commonly used in the papermaking industry, are pulping, screening, centrifugal cleaning, and flotation. The efficiency of each unit operation was evaluated. Mass balances between the inlet and the outlet of each studied operation have been established in order to evaluate the separation efficiency of Ag and cellulosic fibers, the objective being to reuse the fibers to manufacture a recycled paper, and to recover Ag in another fraction for further valorization. The results are encouraging, with more than 70% of silver and over 80% of cellulose fibers recovered, demonstrating a higher recovery efficiency compared to typical recycling methods reported in the literature. Thus, it has been shown that existing processes used in conventional recycling lines can be adapted to efficiently separate functional materials from cellulosic fibers, offering an improvement in both metal and fibers’ recovery.

Power devices developed based on emerging wide bandgap semiconductors have higher requirements for packaging materials, which need to be able to work in more demanding environments. Silver particle sintered materials could be sintered at lower temperatures, work at higher temperatures, and have excellent electrical and mechanical properties, meeting the requirements of new power devices. This article conducts a thorough analysis of the preparation of raw materials, sintering methods, and product properties for sintering silver particles of different sizes through a search of relevant literature. Combined with the current market requirements for packaging materials, the advantages, current problems, and future development trends of sintering silver particles at the nanometer, micrometer, and micro nano composite levels are explored, providing reference for further research and application of silver particle sintering.

Silver-based biocides applied in fabric-based mouth- and nose-covering face masks require characterization due to the potential toxic effects of silver to which users may be exposed. In the absence of reliable silver release data in realistic usage conditions, current safety assessment of face masks relies on a safe-by-design principle. To contribute to the refinement of specifications of safe face masks, types of particulate silver biocides actively applied in face masks on the market were identified and characterized. Ultramicrotomy followed by scanning transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy (STEM-EDX) analysis showed that a wide variety of silver-based biocides were applied. This includes metallic silver nanoparticles (NPs), silver salts in NP form, silver ion exchangers, and notably, various silver nanocomposites with other particulate materials such as synthetic amorphous silica (SAS), TiO2, and ZnO. These composites are added to face masks to combine different modes of biocidal action or to facilitate gradual silver release, thereby extending biocidal activity. In five out of seven silver-containing masks, silver-containing NPs were identified on the surface of fibers. Additionally, significant numbers of other NPs (SAS, TiO2) were found coating the fiber surfaces. Sizes of silver-containing NPs ranged from 3 to 200 nm across all masks, with the large majority of particles below 50 nm. These findings imply that for safety assessment, no-adverse effect levels of all incorporated compounds should be taken into account and that the effects of co-exposure to multiple compounds should be considered. The completion of particle release studies, exposure assessments, and regulatory oversight of face masks is recommended.

Silver nanoparticles (AgNPs) are tiny particles of silver, typically measuring between 1 and 100 nanometers. Their unique physical, chemical, and biological properties have led to their widespread use in various fields, including medicine, electronics, textiles, and environmental science. one of the most remarkable features of AgNPs is their strong antimicrobial activity, which allows them to effectively combat a wide range of pathogens, including bacteria, viruses, and fungi. This property has been utilized in medical products such as wound dressings, coatings for medical devices, and water purification systems. Beyond their antimicrobial capabilities, AgNPs possess notable optical, electrical, and catalytic properties, making them valuable in the development of biosensors, conductive materials, and catalysts for various industrial processes. the synthesis of silver nanoparticles can be achieved through physical, chemical, and biological (green) methods. Physical methods, such as laser ablation and evaporation-condensation, often require sophisticated equipment and significant energy input. Chemical methods, particularly chemical reduction, are widely used due to their simplicity and efficiency but may involve toxic reagents. In contrast, biological methods utilize natural sources like plant extracts, bacteria, and fungi to produce AgNPs in an eco-friendly manner, reducing the reliance on hazardous chemicals.