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Grafting nanomaterials on the carbon fiber (CF) surface is considered an effective strategy for enhancing the interfacial properties of CF-reinforced polymer composites (CFRPs). However, the mechanical properties of the CFs are often compromised during treatment. A new method for in situ growing silver nanoparticles (AgNPs) on the CF surface is proposed in this study. The CFs are first immersed in a low-viscosity silver nitrate solution to form a thin liquid film on the surface. Subsequently, using the abundant active particles in the plasma, the silver ions are reduced to silver atoms and grown into AgNPs on the CF surface. The tensile strength of CF@Ag was 38.74% greater than that of untreated CF, potentially due to the reparative action of AgNPs on defects in CF. The CF showed an evident improvement in surface wettability because of the AgNPs. Furthermore, the interfacial properties were noticeably improved, with the interfacial shear strength of CF@Ag increasing to 91.59 MPa, which was about twice that of pristine CF. Thus, the mechanical properties of composites are significantly improved (flexural strength increased by 190.74%). This study presents a non-destructive and convenient method for growing nanoparticles onto CF to establish a robust interface in CFRPs. [ABSTRACT FROM AUTHOR]

A combination of experimental and numerical investigations on metallic silver and platinum nanoparticles deposited on silica substrates is presented, with a focus on metal–substrate interactions. Experimentally, the nanoparticles, obtained by ultra-high vacuum atom deposition, are characterized by grazing-incidence small-angle x-ray scattering and high resolution transmission electronic microscopy to determine their structure and morphology and, in particular, their aspect ratio (height/diameter), which quantifies the metal–substrate interaction, from the as-grown to equilibrium state. Numerically, the interactions between the metal and the silica species are modeled with the Lennard-Jones (12, 6) potential, with two parameters for each metal and silica species. The geometric parameters were found in the literature, while the energetic parameters were determined from our experimental measurements of the aspect ratio. The parameters are as follows: σAg–O = 0.278 nm, σAg–Si = 0.329 nm, ɛAg–O = 75 meV, and ɛAg–Si = 13 meV for Ag–silica and σPt–O = 0.273 nm, σPt–Si = 0.324 nm, ɛPt–O = 110 meV, and ɛPt–Si = 18 meV for Pt–silica. The proposed Ag–silica potential reproduces quantitatively the unexpected experimental observation of the variation of the aspect ratio for Ag nanoparticles larger than 5 nm, which has been interpreted as a consequence of the silica roughness. The nanoparticle orientation, structure, and disorder are also considered. This metal–silica potential for Ag and Pt should be helpful for further studies on pure metals as well as their alloys. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the biocompatibility of silver nanoparticle (AgNP)-doped Ti-6Al-4V surfaces by evaluating the viability and proliferation rate of human gingival fibroblasts (HGFs)--as the dominant cells of peri-implant soft tissues-- seeded on the modified surfaces. Materials and Methods: AgNPs (sizes 8 nm and 30 nm) were incorporated onto Ti-6Al-4V specimen surfaces via electrochemical deposition, using colloid silver dispersions with increasing AgNP concentrations of 100 ppm, 200 ppm, and 300 ppm. One control and six experimental groups were included in the study: (1) control (Ti-6Al- 4V), (2) 8 nm/100 ppm, (3) 8 nm/200 ppm, (4) 8 nm/300 ppm, (5) 30 nm/100 ppm, (6) 30 nm/200 ppm, and (7) 30 nm/300 ppm. HGF cell primary cultures were isolated from periodontally healthy donor patients and cultured in direct contact with the group specimens for 24 and 72 hours. The cytotoxicity of AgNP-doped Ti-6Al-4V specimens toward HGF was assessed by the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) and BrdU (5-bromo-2'-deoxyuridine) assay tests. Calcein AM and ethidium homodimer (EthD-1) fluorescent stains were used to determine the live and dead cells. The morphology and attachment properties of the HGFs were determined via scanning electron microscopy (SEM). Results: Energy dispersive x-ray (EDX) analysis confirmed the presence of AgNPs on the specimens. The MTT test revealed that AgNPs of both sizes and all concentrations presented a decreased cellular metabolic activity compared to the control discs. All concentrations of both sizes of AgNPs affected the cell proliferation rate compared to the control group, as revealed by the BrdU assay. Overall, cytotoxicity of the modified Ti-6Al-4V surfaces depended on cell exposure time. Observation via confocal microscopy confirmed the results of the MTT and BrdU assay tests. Specifically, most cells remained alive throughout the 72-hour culture period. SEM images revealed that adjacent cells form bonds with each other, creating confluent layers of conjugated cells. Conclusions: The findings of the present study indicate that Ti-6Al-4V surfaces modified with 8 nm and 30 nm AgNPs at concentrations of 100 ppm, 200 ppm, and 300 ppm do not produce any serious cytotoxicity toward HGFs. The initial arrest of the HGF proliferation rate recovered at 72 hours. These results on the antibacterial activity against common periodontal pathogens, in combination with the results found in a previous study by the same research group, suggest that AgNP-doped Ti-6Al-4V surfaces are potential candidates for use in implant abutments for preventing peri-implant diseases. [ABSTRACT FROM AUTHOR]

Enantio-discrimination and spin-dependent electrochemistry (SDE), as a manifestation of the chirality-induced spin selectivity (CISS) effect, are important phenomena that can be probed by "chiral" electrochemistry. Here, we prepared chiralized surfaces of gold and nickel, to serve as working electrodes, through effective chemisorption of enantiopure dimethyl-bis(ethylenedithio)-tetrathiafulvalene (DM-BEDT-TTF) 1, tetramethyl-bis(ethylenedithio)-tetrathiafulvalene (TM-BEDT-TTF) 2, and their capped silver nanoparticle (AgNPs) aggregate by simple incubation of the metallic substrates. The effective chemisorption was checked by means of ultrahigh vacuum x-ray photoelectron spectroscopy (XPS) and by electro-desorption experiments, i.e., cyclic voltammetry (CV) scans showing a first electro-desorption peak at about −1.0 V. The Au|1 and Au|2 chiral electrodes were successfully used in CV experiments exploiting chiral redox probes. Finally, the hybrid interfaces Ni|enantiopure 1 or 2|AgNPs served as working electrodes in SDE experiments. In particular, the hybrid chiral interfaces Ni|(R)-2|AgNPs and Ni|(S)-2|AgNPs exhibited a significant spin-filtering ability, as a manifestation of the CISS effect, with average spin polarization values of 15%. [ABSTRACT FROM AUTHOR]

The development of electrodes for hydrogen evolution via water splitting in a neutral electrolyte is highly desirable, especially considering that natural water resources such as seawater typically have a neutral pH. In this study, silicon nanowires (SiNWs) arrays with uniform silver (Ag) decoration are prepared as a cathode material, which exhibits excellent and stable electrochemical performance for neutral water electrolysis. Ag ions, utilized in the preparation of SiNWs through metal-assisted chemical etching technique, are retained and decorated within the SiNWs array without undergoing a dissolution process, referred to as Native SiNWs. Remained Ag+ ions on the SiNWs are activated photocathodically and reduced to Ag0, resulting in a significantly enhanced performance as an electrocatalyst for hydrogen evolution reaction (HER). Hence, this photocathodic activation of Native SiNWs (PCA-Native SiNWs) eliminates the need for additional cocatalyst deposition for HER, utilizing the Ag ions employed in the SiNWs preparation process. This enhancement in HER activity is exclusively observed by photocathodic activation, not by cathodic activation without light irradiation, indicating the crucial role of photoelectrons in SiNWs under light irradiation for the activation. Additionally, the nanowire structure serves as an ideal platform for Ag nanoparticles, providing sufficient surface area, resulting in excellent dispersion and an increased number of active sites. Furthermore, PCA-Native SiNWs demonstrates outstanding electrochemical stability for over 60 h, with no significant reduction in current density or structural degradation in a neutral electrolyte. Several characterizations and electrochemical analyses have been conducted to elucidate the in-situ decoration of Ag nanoparticles on SiNWs and investigate the surface chemistry for the activation mechanism. This work introduces a new perspective on using Ag-decorated SiNWs directly as an electrocatalyst for effective hydrogen evolution in a neutral media. Saleem et al., "A Strategy to Reutilize Silver Nanoparticles on Silicon Nanowires via Photocathodic Activation for Enhanced and Sustainable Hydrogen Evolution"Native SiNWs, which are prepared by retaining Ag nanoparticles during SiNW synthesis, exhibited better performance for HER than SiNWs. Additionally, the retained Ag can be more evenly distributed and reduced during photocathodic activation, resulting in significantly improved HER activity. [Display omitted] • Photocathodically activated Native SiNWs (PCA-Native SiNWs) are developed. • Retained Ag ions on SiNWs are reduced and activated by light irradiation and cathodic potential (photocathodic activation). • Reduced Ag enhances electrochemical performance of SiNWs as an electrocatalyst. • Ag nanoparticles are evenly distributed vis the dissolution-redeposition phenomenon. • PCA-Native SiNWs show stable activity in neutral pH. [ABSTRACT FROM AUTHOR]

Dopamine (DA) is a potent neuromodulator in the brain that affects a wide range of motivated behaviors. Abnormal concentration of DA is related to a variety of diseases. Hence, it is imperative to establish a rapid and precise method for quantifying DA. In this work, we integrate orange-yellow emissive carbon dots (CDs) with target-induced silver deposition on gold nanoparticles (Au NPs), forming gold/silver core-shell nanoparticles (Au@Ag NPs), to construct a fluorometric and colorimetric dual-signal sensor for sensitive detection of DA. Au NPs and silver ions (Ag+) have minimal effect on the fluorescence of CDs. DA can reduce the silver ions to Ag(0) on the surface of the Au NPs to form a silver shell, resulting in the blue-shift of the absorbance peak from 520 to 416 nm, which overlaps with the excitation spectrum of CDs. As a result, the system color turns from pink to orange-yellow, and the fluorescence of CDs is quenched due to the strong inner filter effect. The linear range of the colorimetry is 0.5–18 μM with a limit of detection (LOD) of 0.41 μM, while the linear range for the fluorometry method is 0.5–14 μM with a LOD of 0.021 μM. This method demonstrates notable advantages including a low detection limit, rapid response time, and straightforward operation in practical samples, showing great potential in biomedical analysis. [ABSTRACT FROM AUTHOR]

By combining mechanical treatment of aluminium alloy with subsequent surface modification using micro-arc oxidation (MAO) technology, zinc oxide (ZnO) oxide coatings were prepared, which achieved enhanced hydrophobic properties, excellent antibacterial activity and corrosion resistance. The coatings were oxidised at different MAO discharge intensities using different frequencies. All surfaces were subjected to determination of wettability, corrosion resistance and chemical stability at 1, 7, 14, and 28 days and antibacterial activity of the coatings against the bacterial population of Staphylococcus aureus, Escherichia coli with an evaluation of population inhibition after 24 h. The surfaces mechanically modified by blasting showed a hydrophobic character; their subsequent oxidation by MAO contributed to a significant increase in hydrophobic properties. The sample with the highest Zn content (1.1 wt%), prepared at an MAO source frequency of 222 Hz, i.e. at the most intense plasma discharge, showed the most significant chemical stability in simulated body fluid (SBF) and distilled water and showed the highest antibacterial activity after 24 h. Thus, blasting of aluminium alloy surfaces and their subsequent MAO in alkaline electrolyte allows to obtain oxide coatings with antibacterial, hydrophobic and corrosion-resistant properties with the possibility of their use on surfaces with potential occurrence of harmful bacteria. • Oxide layers on aluminium alloy were prepared in alkaline electrolyte. • Frequencies of 49, 95 and 222 Hz, blasting and MAO technology combination were used. • Mechanically modified layers and MAO coatings achieved hydrophobic properties. • ZnO-doped MAO coatings had antibacterial properties and higher corrosion resistance. [ABSTRACT FROM AUTHOR]

In the present study, pyroligneous acid, also known as wood vinegar, has been employed as reducing and stabilizing agent in the synthesis of silver nanoparticles (AgNPs) anchored on nanocellulose (NC). The idea is to confer the latter bactericidal properties for its typical uses such as in cosmetics and food-packing. It has been demonstrated that AgNPs can be directly produced onto NC in one-pot fashion while dramatically enhancing the kinetics of AgNPs synthesis (2 h for reaction completion) in comparison to the NC-less counterpart (10 days for reaction completion). Furthermore, NC allowed for a narrower size distribution of AgNPs. NC-supported and non-supported AgNPs had sizes of 5.1 ± 1.6 nm and 16.7 ± 4.62 nm, respectively. Immortalized human keratinocytes (HaCat) cells were then employed as model to evaluate the cytotoxicity of the AgNPs-NC compound. The latter was found not to impact cell proliferation at any formulation, while decreasing the viability by only 6.8% after 72 h. This study contributes to the development of more environmentally benign routes to produce nanomaterials and to the understanding of their impact on cells. [ABSTRACT FROM AUTHOR]

ABSTRACT A multifunctional nanostructured hybrid composed of metal–protein–ceramic was designed and then synthesized using three different methods: chemical reduction, physical adsorption, and coprecipitation. The processes yielded colloidal spherical silver nanoparticles (AgNPs) enveloped in a bovine serum albumin (BSA) corona, leading to the core–shell structure AgNPs–BSA. To enhance biocompatibility and mitigate potential toxicity associated with metallic nanoparticles, this core–shell structure was coated with a layer of calcium carbonate (CaCO3). In order to analyze the internal structure of the resulting hybrid nanostructure (AgNPs–BSA–CaCO3), a number of samples were produced by focused ion beam (FIB) and characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and zeta potential (ζ) measurements. The cytotoxic effect of the samples were evaluated through in vitro tests on mouse macrophage cell line RAW 264.7 ATCC TIB‐71, this was accomplished by calculating the appropriate concentrations from the dose–response curve of AgNPs. Research showed that the AgNPs–BSA–CaCO3 mixture triggered the formation of vaterite; these findings were corroborated by FTIR and Raman techniques. The spherical nanostructures have an average diameter size of 4.3 ± 2 μm and an average roughness (Ra) of 3.11 ± 0.62 μm. Zeta potential (ζ) and isoelectric point studies reveal that this hybrid nanostructure exhibits amphoteric behavior that differs from either AgNPs or AgNPs–BSA alone. Cell viability response exceeded 75%, indicating the noncytotoxic nature of the proposed hybrid nanostructures. [ABSTRACT FROM AUTHOR]

ABSTRACT The biogenic synthesis of silver nanoparticles (AgNPs) with leaf extract Abution indicum was done, and those were characterized by ultraviolet–visible spectroscopy (UV–vis), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), powder X‐ray diffraction (PXRD), field emission scanning electron microscopy (FESEM) and transmission electron microscope (TEM) with energy‐dispersive X‐ray (EDX) spectroscopy. The analysis by UV–vis spectroscopy showed a peak of 450 nm, and DLS and zeta potential were utilized to determine the size distribution of the biosynthesized Abution indicum–AgNPs (AI‐AgNPs) with a size range of 24–37 nm, and the X‐ray diffraction peak 38.096o was used to confirm that the crystalline structure of AI‐AgNPs. Furthermore, the antipathogenic effect of synthesized AgNPs and standard antibiotic (Ciprofloxacin) as studied the positive control in different types of bacterial pathogens likes Staphylococcus aureus and Escherichia Coli, with the zone of inhibition values of 9 mm. The synthesized AgNPs displayed excellent photocatalytic activity against reactive blue under sunlight than a UV light irradiation, and maximum degradation of 43% was achieved with 66 min of reaction time. In view of promising activity, the AgNPs could be used photocatalyst for the degradation of dyes in wastewater, and pomegranate leaf extract can be applied as eco‐benign and cost‐effective approach for AgNPs synthesis. Hence, the current findings suggest that Abutilon indicum is a valuable source for tailoring the potential of AgNPs toward various enhanced biological, photocatalytic, and adsorption activities. Consequently, the plant biological molecule‐mediated synthesized AI‐AgNPs could be excellent contenders for future therapeutic applications. [ABSTRACT FROM AUTHOR]

A highly selective, label-free, surface-enhanced Raman spectroscopy (SERS) based sensor platform employing hollow carbon nanofibers functionalized with silver nanoparticles (Ag@HCNFs) has been developed to monitor anomalous concentrations of potential biomarkers, such as salivary nitrite facilitating pre-diagnosis of oral cancer. Co-axial electrospinning was used for the fabrication of the nanofibrous Ag@HCNFs followed by thermal treatment of PAN/PVP core–shell nanofibers and chemical reduction of silver nanoislands. The developed plasmonic Ag@HCNFs was structurally and morphologically characterized using X-Ray diffraction, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy, which clearly demonstrated the successful anchoring of silver nanoparticles on hollow carbon nanofibers. The properties of Ag@HCNFs showed significant SERS enhancement of the order of 107 with a detection limit of 10−11 M with R6G, demonstrating its efficacy to investigate real-time salivary samples, particularly towards the detection of salivary nitrite within the clinically relevant range (50 μM–300 μM) towards the pre-diagnosis of oral cancer. The proposed SERS-based salivary platform has the potential to be used as a low-cost, non-invasive pre-diagnostic tool for early diagnosis and mass screening of oral cancer. [ABSTRACT FROM AUTHOR]

Long-term antibiotic treatment results in the increasing resistance of bacteria to antimicrobials drugs, so it is necessary to search for effective alternatives to prevent and treat pathogens that cause diseases. This study is aimed for biological synthesis of silver Carthamus nanoparticles (Ag-Carth-NPs) to combat microbial biofilm formation and Pseudomonas aeruginosa virulence genes. Ag-Carth-NPs are synthesized using Carthamus tenuis aqueous extract as environmentally friendly method has no harmful effect on environment. General factorial design is used to optimize Ag-Carth-NPs synthesis using three variables in three levels are Carthamus extract concentration, silver nitrate concentration and gamma radiation doses. Analysis of response data indicates gamma radiation has a significant effect on Ag-Carth-NPs production. Ag-Carth-NPs have sharp peak at λ max 425 nm, small and spherical particles with size 20.0 ± 1.22 nm, high stability up to 240 day with zeta potential around − 43 ± 0.12 mV, face centered cubic crystalline structure and FT-IR spectroscopy shows peak around 620 cm−1 that corresponding to AgNPs that stabilized by C. tenuis extract functional moiety. The antibacterial activity of Ag-Carth-NPs against pathogenic bacteria and fungi was determined using well diffusion method. The MIC values of Ag-Carth-NPs were (6.25, 6.25, 3.126, 25, 12.5, 12.5, 25 and 12.5 µg/ml), MBC values were (12.5, 12.5, 6.25, 50, 25, 25, 50 and 25 µg/ml) and biofilm inhibition% were (62.12, 68.25, 90.12, 69.51, 70.61, 71.12, 75.51 and 77.71%) against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, Candida tropicalis and Candida albicans respectively. Ag-Carth-NPs has bactericidal efficacy and significantly reduced the swarming, swimming motility, pyocyanin and protease production of P. aeruginosa. Furthermore, P. aeruginosa ToxA gene expression was significantly down regulated by 81.5%, while exoU reduced by 78.1%, where lasR gene expression reduction was 68%, while the reduction in exoU was 66% and 60.1% decrease in lasB gene expression after treatment with Ag-Carth-NPs. This activity is attributed to effect of Ag-Carth-NPs on cell membrane integrity, down regulation of virulence gene expression, and induction of general and oxidative stress in P. aeruginosa. Ag-Carth-NPs have no significant cytotoxic effects on normal human cell (Hfb4) but have IC50 at 5.6µg/mL against of HepG-2 cells. Limitations of the study include studies with low risks of silver nanoparticles for in vitro antimicrobial effects and its toxicity. [ABSTRACT FROM AUTHOR]

In this work, silver nanoparticles (AgNPs) were elaborated using a simple, low-cost, and reproducible method by thermal treatment at 90°C of chitooligosaccharides (COSs), produced by chitosan depolymerization using the digestives chitosanases from Portunus segnis viscera, in the presence of AgNO3. The characterization of the obtained AgNPs, using UV-visible spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS), and Fourier-transform infrared (FTIR) spectroscopy analyses, showed that they are crystalline, spherical and stable for a month at 4°C. Moreover, the biological properties of the synthesized AgNPs were evaluated, proving that they exhibited interesting antioxidant and antibacterial activities. The present investigation suggested that COSs will be a good source for the preparation of AgNPs that could be useful in different industrial and biomedical applications. [ABSTRACT FROM AUTHOR]

In this investigation, we detail the synthesis of silver nanoparticles (AgNPs) via a precise chemical vacuum deposition (CVD) methodology, aimed at augmenting the analytical performance of laser desorption/ionization mass spectrometry (LDI-MS) for the detection of low-molecular-weight analytes. Employing a precursor supply rate of 0.0014 mg/s facilitated the formation of uniformly dispersed AgNPs, characterized by SEM and AFM to have an average diameter of 33.5 ± 1.5 nm and a surface roughness (Ra) of 11.8 nm, indicative of their homogeneous coverage and spherical morphology. XPS and SEM-EDX analyses confirmed the metallic silver composition of the nanoparticles with Ag peak splitting, reflecting the successful synthesis of metallic Ag. Comparative analytical evaluation with traditional MALDI matrices revealed that AgNPs significantly reduce signal suppression, thereby enhancing the sensitivity and specificity of LDI-MS for low-molecular-weight compounds such as triglycerides, saccharides, amino acids, and carboxylic acids. Notably, the application of AgNPs demonstrated a superior linear response for triglyceride signals with regression coefficients surpassing 0.99, markedly outperforming conventional matrices. The study further extends into quantitative analysis through nanoparticle-based laser desorption/ionization (NALDI), where AgNPs exhibited enhanced ionization efficiency, characterized by substantially lower limits of detection (LOD) and quantification (LOQ) for tested standards. Particular attention was paid to lipids with a detailed examination of their fragmentation pathways. These results highlight the significant potential of AgNPs synthesized via CVD to transform the analytical detection and quantification of low-molecular-weight compounds using NALDI. This approach offers a promising avenue for expanding the scope of analytical applications in mass spectrometry and introducing innovative methodologies for enhanced precision and sensitivity. [ABSTRACT FROM AUTHOR]

COVID‐19 the most devastating pandemic of the current millennium, can survive from hours to months in environment, devices, and surface. Its transmission by asymptomatic carriers has significantly strained the existing testing resources. At present, there are no clinically proven therapeutic methods that effectively inhibit the effects of this virus. Nanoparticles (NPs) have been extensively utilized in various medical applications, including biosensing, drug delivery, imaging, and antimicrobial/antiviral treatment. Synthetic NPs can closely resemble the virus and strongly interact with its proteins due to their similar morphology. Therefore, NP‐based strategies for combating this virus hold immense potential and may reduce the survivability of the virus in the environment due to unique physicochemical features and surface modification properties. In this study, antiviral properties of silver (Ag), copper oxide (CuO), cobalt oxide (Co3O4), and cerium oxide (CeO2) NPs besides Ag and Cu sheets against COVID‐19 in nasopharyngeal samples were investigated. All NPs suspensions were prepared in Virus Transporter Media (VTM) in 25, 50, and 100 mg/mL concentrations, additionally, Cu and Ag sheets were added to SARS‐CoV‐2 virus pooled and then incubated at room temperature. Viral RNA was extracted from those suspensions after different incubation times and concentrations and quantitative polymerase chain reaction (qPCR) analysis was performed. For virucidal activity evaluation, the estimated lysed virus copy number was assessed according to the pooled virus sample serial dilution and eventually based on changes in the cycle threshold (CT) of qPCR. According to CT number changing after incubation of NPs with pooled virus sample, CuO NPs had the greatest virus inactivation on virus lysis at all concentrations and times while Co3O4 NPs showed moderate antiviral activity (P<0.05). The antiviral activity of other NPs was less than CuO and Co3O4 and were almost identical at similar concentrations and times. Cu and Ag sheets have shown a direct linear relationship between incubation time and antiviral activity. Cu nanoparticles had significant destructive effects on the SARS‐CoV‐2 virus among all nanoparticles, and the Cu sheet had considerably less antiviral activity than its own Cu NPs. These findings might make it helpful to use CuO NPs in masks, and air/water filters, make coated surfaces with effective NPs, and manufacture disinfectant solutions to combat coronaviruses and other viruses that can cause respiratory infections. [ABSTRACT FROM AUTHOR]

A novel inorganic‐organic‐inorganic ternary bioactive material formulated on antimicrobial peptide‐based polymer has been reported. Supramolecular approach has been employed to incorporate molecularly crowded tyrosine‐based polymer stabilized silver nanoparticles into membrane bound vesicles exploiting polyoxometalate‐triggered surface templating strategy. Utilizing the covalent reversible addition fragmentation chain transfer (RAFT) polymerization and exploiting templated supramolecular architectonics at biopolymer interface, the bioactive ternary polymeric nanohybrids have been designed against Shigellosis leveraging the antibacterial activities of silver nanoparticle, cationic amphiphilic tyrosine polymer and inorganic polyoxometalate. The detail investigation against Shigella flexneri 2a cell line demonstrates that the collaborative mechanism of the ternary hybrid composite enhances the bactericidal activity in comparison to only polyoxometalate and polymer stabilized silver nanoparticle with an altered mechanism of action which is established via detailed biological analysis. [ABSTRACT FROM AUTHOR]

Purpose: The antibacterial properties of silver nanoparticles (AgNPs) are extensively identified. In large quantities, they might be harmful. So many fields of nanotechnology have shown a great deal of interest in the development of an environmentally friendly, efficient method for synthesizing metal nanoparticles. Because of its antibacterial and antifungal properties toward a wide range of microbes, chitosan silver nanoparticles (AgNPs@Cs) constitute a newly developing class of bio-nanostructured hybrid materials. Furthermore, the use of photothermal therapy (PTT) has been suggested as a means of elimination of germs. These light-stimulated treatments are minimally invasive and have a few side effects. In the present work, the antibacterial effect of AgNPs at low concentrations; prepared by chemical and green methods as antimicrobial and photothermal agents in photothermal therapy; with laser irradiation were explored as combined treatment against MRSA, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Methods: Silver nanoparticles were produced in two ways. First, by sodium borohydrides, second, by chitosan (as a natural eco-friendly reducing, and capping agent). The nanostructure of AgNPs and AgNPs@Cs was confirmed by UV–visible spectrometer, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIRs), and direct light scattering (DLS). The antibacterial activity of the prepared nanoparticles and the laser irradiation was tested against three bacterial species of zoonotic importance; MRSA, Pseudomonas aeruginosa, and Klebsiella pneumoniae; and was evaluated by measuring their minimum inhibitory concentrations (MIC). Results: Silver nanoparticles produced by the two methods had spherical shapes with nearly the same particle size. The analysis of DLS showed that AgNPs were very stable with zeta potential − 28.8 mv, and 47.7 mv by chemical and chitosan synthesis, respectively. Furthermore, AgNPs@Cs showed higher antibacterial activity toward the tested bacterial species than AgNPs by chemical method. Additionally, the bacterial viability using photothermal laser therapy was reduced compared to laser and AgNPs alone. The bactericidal activities were higher when laser diode was coupled with AgNPs@Cs than by chemical reduction. Conclusion: The laser combined treatment had a higher antimicrobial effect than AgNPs alone or laser irradiation alone. [ABSTRACT FROM AUTHOR]

Give the emergence of drug resistance in bacteria resulting from antibiotic misuse, there is an urgent need for research and application of novel antibacterial approaches. In recent years, nanoparticles (NPs) have garnered significant attention due to their potential to disrupt bacteria cellular structure through loading drugs and special mechanisms, thus rendering them inactive. In this study, the surface of hollow polydopamine (HPDA) NPs was utilized for the growth of Prussian blue (PB), resulting in the formation of HPDA-PB NPs. Incorporation of Co element during the preparation process led to partial doping of PB with Co2+ ions. The performance test results demonstrated that the HPDA-PB NPs exhibited superior photothermal conversion efficiency and peroxidase-like activity compared to PB NPs. HPDA-PB NPs have the ability to catalyze the formation of hydroxyl radicals from H2O2 in a weakly acidic environment. Due to the tiny PB particles on the surface and the presence of Co2+ doping, they have strong broad-spectrum antibacterial properties. Both in vitro and in vivo evaluations confirm their efficacy against various bacterial strains, particularly Staphylococcus aureus, and their potential to promote wound healing, making them a promising candidate for advanced wound care and antimicrobial applications. [ABSTRACT FROM AUTHOR]

The surface-enhanced Raman scattering (SERS) performance and photocatalytic degradation of dye molecules absorbed on Ag nanoparticle-decorated ZnO microrods are investigated at 20 and 50 °C. The role of temperature in the mechanism is elucidated. This work provides insight into the optimization of temperature-dependent plasmon-induced catalysis using similar materials. [ABSTRACT FROM AUTHOR]

The alarming rise of pathogen antibiotic resistance presents a major global health challenge and demands a novel way to control the microbial infections. Simultaneously, nanotechnology has found numerous uses in electrical as well as electronic systems, including timing, filtering, power factor adaptation, and capacitors for energy storage. This work investigates the synthesis and characterization of a silver nanoparticle (AgNPs) utilizing Calotropis procera (CPL) leaf extract. The optimization of synthesis process and the reduction of nanoparticles (NPs) were validated by UV–visible spectroscopy. AgNPs' was exhaustively characterized for morphology, crystallinity, zeta-potential, and structural properties. The produced NPs demonstrated a wide range of characteristics, such as antioxidant, antidiabetic, antibacterial, and antifungal effects. Furthermore, remarkable electrochemical performance was indicated by the CPL-AgNPs electrode, which has mesoporous, clustered sphere-shaped particles onto a flexible stainless-steel substrate. This highlights the electrode's potential in energy storage applications. Copper monosulfide served as the anode and CPL-AgNPs as the cathode electrode in tested hybrid supercapacitor devices, which proved remarkable specific capacitances, high specific energy, and exceptionally high specific power. In order to address the twin challenges of antimicrobial resistance alongside advanced energy storage, this study provides a novel and thorough analysis of the basic electrochemistry as well biological properties of AgNPs, clarifying their potential storage of charges mechanisms and biomedical applications. Highlights: CPL-AgNPs exhibited improved biomimetic attributes. Antibiotic resistance against pathogens were challenged through use of CPL-AgNPs. Supercapacitor application of facile synthesized AgNPs for the first time demonstrated improved physical application. [ABSTRACT FROM AUTHOR]

This study is a further scale-up trial from the previously reported process optimization study on the green synthesis of silver nanoparticles (AgNPs) using Indonesian medicinal plant extracts. The present study utilized Phyllanthus niruri (PN) herb extracts, Orthosiphon stamineus (OS) leaf extracts, and Curcuma longa (CL) rhizome extracts as reducing agents to synthesize AgNPs on a larger scale. Upscaling increased the synthesis volume (from 100 mL to 1000 mL) and the centrifugation volume (from 1 mL to 40 mL) at various durations at 70°C for 60 min. The results showed that the minimum centrifugation duration to obtain optimal AgNPs was 5 minutes. The formation AgNPs were then characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), particle size and zeta potential analyzer, and X-ray diffractometer (XRD). The results showed the spherical silver nanoparticles with an average particle size (MI) of 169 nm (PN), 179.1 nm (OS), and 623 nm (CL), polydispersity index (PDI) value of 0.2202 (PN), 0.2579 (OS), and 0.00872 (CL) and the face-centered cubic (fcc) crystal structure. The green synthesis method using PN and OS extracts proved effective, environmentally friendly, safe, and cost-effective for the synthesis of AgNPs. The findings of this study have the potential to provide a green synthesis method for the production of AgNPs on a larger scale. [ABSTRACT FROM AUTHOR]

This study explores the corrosion resistance and antibacterial properties of a PTFE + TiO2/Ag coating applied to 316 L stainless steel. To enhance adhesion, a polydopamine interlayer was chemically deposited onto the steel surface. The PTFE + TiO2 coating was subsequently applied through immersion, followed by the deposition of silver nanoparticles using a chemical method. Optimization of the polydopamine interlayer involved varying temperature, time, stirring speed, and drying parameters. The optimal conditions for the polydopamine interlayer were determined to be 60 °C for 1 h, 300 rpm stirring, and 24-h drying in a freeze dryer. Analytical results demonstrated that both the PTFE + TiO2 and PTFE/PTFE + TiO2/Ag coatings exhibited exceptional corrosion resistance, with corrosion currents of 3.3 × 10−5 and 3.2 × 10−4 μA/cm2, respectively. Antibacterial assessments showcased the remarkable ability of the PTFE/PTFE + TiO2/Ag coating, containing 5% silver content, to effectively inhibit bacterial penetration within a 6.5 mm radius. Furthermore, this coating displayed a water contact angle of 143°, classifying it as a hydrophobic coating. The photocatalytic efficiency (Rs) was determined to be 3.18 × 10−3 A/W, a performance level comparable to that of a standard UV sensor. These findings underscore the substantial enhancements in corrosion resistance, antibacterial performance, and hydrophobic characteristics achieved with the PTFE + TiO2/Ag coating, particularly through the novel optimization of the polydopamine interlayer. This coating exhibits great promise for multifunctional protective applications in diverse fields, particularly demonstrating its suitability for implants and bio-coatings. [ABSTRACT FROM AUTHOR]

Antibiotic success rates are decreasing as drug-resistant bacteria become more prevalent, prompting the development of new therapeutic drugs. Herein, we demonstrated the antimicrobial activity of sarsaparilla root extract fabricated silver nanoparticles (sAgNPs). The UV–Visible spectra revealed that the surface Plasmon resonance maxima of sAgNPs were at 415 nm. Transmission electron microscopy confirms that the particles are spherical with size of 12–35 nm. The minimum inhibitory concentration (MIC) of sAgNPs against Escherichia coli, uropathogenic Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus was 62.5, 62.5, 62.5, 62.5, 125 and 125 µM, respectively. At 1X MIC, sAgNPs induces excess reactive oxygen species (ROS) production and disturbs the bacteria membrane intergity, causing cytoplamic membrane depolarization. Interestingly, antibacterial activity of sAgNPs was considerably reduced in the presence of an antioxidant, N-acetyl cysteine, suggesting that ROS-induced membrane damage is a plausible cause of cell death. In contrast to many studies that only report the in vitro activity of NPs, we determined the in vivo antibacterial efficacy using the zebrafish model. It was found that sAgNPs protect fish from infection by inhibiting bacterial growth and eliminating them from the fish. In addition, the catalytic potential of sAgNPs for wastewater decontamination was demonstrated by degrading organic pollutants such as methyl orange, congo red, reactive black, and acid blue. The pollutants degraded in less than 10 min, and the reaction follows pseudo-first-order kinetics. As a proof of concept, the catalytic potential of sAgNPs in degrading mixed dyes to satisfy industrial wastewater treatment needs was established. In summary, sAgNPs have the potential to act as nanocatalysts and nano-drugs, addressing key challenges in medical and environmental research. [ABSTRACT FROM AUTHOR]

In this work, new pH‐sensitive and antibacterial drug carrier systems based on silver nanoparticles (AgNPs) embedded in the interlayer of laponite (Lap) in the presence of chitosan (CTS) for the controllable release of sunitinib maleate (STM) were developed. Silver ions and sunitinib maleate were first loaded into Lap, and the CTS‐based hybrid bionanocomposite carrier (Lap@CTS@AgNPs@STM) was obtained in the presence of citric acid as a cross‐linker agent. The successful preparation of nanocarrier and Ag NPs formation was thoroughly confirmed using techniques such as FTIR, XRD, TGA, SEM, and TEM. TEM images illustrated the excellent distribution of Ag NPs in the structure of Lap@CTS@AgNPs. The as‐prepared samples showed a pH‐sensitive anticancer drug release behavior. The STM release mechanism was studied using Korsmeyer–Peppas and Higuchi kinetic models. Furthermore, the in vitro cytotoxicity and antibacterial tests were carried out against both bacteria S. aureus and E. coli and MCF‐7 cell lines, respectively, to prove the effectiveness of synthesized samples as multifunctional carrier systems for biomedical applications. [ABSTRACT FROM AUTHOR]

This study is aimed at the synthesis of nanoparticles (NPs) and nanocomposite (NC) using maize leave as precursor. Silver NPs (AgNPs) and AgNCs were synthesized from silver nitrate and maize leave extract using green approach. The maize leave NPs (AgNPs) and the maize leave NCs (AgNCs) were characterized using Fourier Transform infrared (FTIR), scanning electron microscopy (SEM), energy dispersion x-ray (EDX), Brunauer–Emmett–Teller (BET) surface area measurement, and dynamic light scattering (DLS) particle size analysis. The phytochemical analysis revealed the presence of tannin, oxalate, and flavonoids in appreciable quantity, which have proven to be a powerful reducing agent that facilitates the reduction of silver ions for the synthesis of silver NPs and silver nano composites. FTIR revealed that all the peaks identified in AgNPs and AgNCs belong to the characteristic bands of reducing compounds such as flavonoid compounds. The SEM-EDX results showed that the peaks observed from 2.9 to 3.1 Kev in the spectra indicate the presence of elemental silver as it is reduced from Ag+ to Ag. DLS analysis results showed that the average size and polydispersity index (PdI) of the synthesized AgNPs and AgNCs were 42.30 and 68.29 nm, 0.691 and 0.270, respectively. The single point BET surface area (m2/g) obtained for AgNPs and AgNCs were 223.3 and 209.5, respectively. The results showed maize leave as a potential precursor for the preparation of NPs and NCs. [ABSTRACT FROM AUTHOR]

This paper presents a novel binder-free electrochemical synthesis of a porous ternary composite comprising polyaniline/multiwall carbon nanotubes decorated with silver nanoparticles (Ag@PANI/MWCNTs), which serves dual functions as a photocatalyst for methylene blue degradation and as an electrode for high-performance supercapacitors application. Various characterization techniques confirm that the synthesized Ag@PANI/MWCNTs composite exhibits excellent optical, chemical, electrical, structural, morphological, electrochemical and photocatalytic characteristics. The composite exhibits excellent electrochemical and photocatalytic efficacy attributed to its porosity, higher surface area, conductivity and rapid redox properties. Electrochemical tests reveal specific capacitance of 862 F/g, energy density of 65.78 Whkg−1, power density of 444.44 Wkg−1 and cycling stability with 79% capacitance retention even after 10,000 cycles. As a photocatalyst, the composite achieves approximately 95% degradation in 25 min with reusability up to five cycles. It also exhibits high transient photocurrent responses (0.36 mA/cm2) and a high-rate constant (0.13 min−1), confirming excellent photocatalytic activity. The synergistic effect of PANI/MWCNTs and the incorporation of Ag nanoparticles contribute to the outstanding performance of the synthesized nanocomposite. Thus, it is expected that the synthesized Ag@PANI/MWCNT is a promising ternary composite which may prove to be a noble material for photocatalytic and energy storage-related devices. [ABSTRACT FROM AUTHOR]

Antibacterial dressings play an important role in wound management, especially in chronic wounds. Due to the excellent water retention, antibacterial hydrogel has become an ideal wound dressing. In this paper, the effective antibacterial dressing was constructed with the poly N-isopropylacrylamide (PNIPAM) hydrogel and graphene oxide loading nanosilver particles (GO-Ag) by the in situ chemical crosslinking method. The molecular structure, viscosity and mechanical properties, antibacterial agent content, antibacterial performance, temperature-sensitive antibacterial relationship and biocompatibility of PNIPAM-based GO-Ag composite hydrogel (PNIPAM/GO-Ag) were systematically characterized by the scanning electron microscopy (SEM), infrared spectroscopy (FT-IR), plate counting and other methods. The results showed that the introduction of GO-Ag increased the pore structure of PNIPAM/GO-Ag hydrogel and provided more active sites for the release of silver nanoparticles, wherein the content of nanosilver in PNIPAM/GO-Ag hydrogel was only 0.01%, meeting the requirements of application as antibacterial dressings. Moreover, when the hydrogel was subjected to heat contraction, silver nanoparticles could release more quickly and efficiently. The antibacterial rates of the PNIPAM/GO-Ag hydrogel against E. coli and S. aureus were 99.8 and 99% at 37 °C, respectively, higher than those at 25 °C (92, 95%). Compared with the pure PNIPAM hydrogel (1423.0%), the swelling rate of PNIPAM/GO-Ag hydrogel could reach 2024.6%, certifying its ability to absorb exudate of wound site. When the deformation was less than 80%, the hydrogel could maintain excellent elastic deformation recovery ability, and the viscosity of hydrogel at human body temperature was 38 Pa·s. These prove that it had a good fit with the skin, could dissipate more energy and restore shape. The hemolysis rate of PNIPAM/GO-Ag hydrogel was less than 5%, showing good bio-safety. These all demonstrated the PNIPAM/GO-Ag hydrogel can be used as a potential application for the skin wound dressing. [ABSTRACT FROM AUTHOR]

The green synthesis of noble metal nanoparticles has gained a lot of interest in the area of nanotechnology, because of its high therapeutic properties. The present study focussed on the synthesis of the silver nanoparticles (Ag-NPs) using Ceropegia debilis leaf extract and characterized by various physio-chemical techniques and surface morphological studies. The prepared Ag-NPs exhibit a face-centred cubic structure, spherical morphology, and high purity as shown by XRD, SEM, and EDS analyses. The average size of the Ag-NPs was confirmed by TEM study as 18.6 ± 7.5 nm. The synthesized Ag-NPs show remarkable antioxidant activity of 72.1% compared to standard BHT 86.9%. Furthermore, Ag-NPs show remarkable cytotoxic properties against MCF 7 and A 549 cell line of 37.19% and 33.33%, respectively at 250 µg/mL. The antibacterial activity of Ag-NPs was investigated against the human pathogen and intestinal pathogen Staphylococcus aureus and Escherichia coli by agar disc diffusion method. Moreover, the synthesised Ag-NPs exhibit good antifungal properties against the fungal specimen Trichoderma viride assessed by well diffusion technique. In addition, Ag-NPs serve as an excellent nanocatalyst in the removal of toxic methylene blue dye (93.2%) from industrial wastewater under sunlight irradiation. [Display omitted] • Silver nanoparticles were synthesized by Ceropegia debilis extract. • SEM and TEM used for surface morphology and size determination. • Impressive anti-proliferative activity towards MCF 7 and A 549 were observed. • Effective nanocatalyst for the degradation of methylene blue dye. [ABSTRACT FROM AUTHOR]

The green synthesis of silver nanoparticles offers a non-toxic, eco-friendly, economical, and efficient solution against various microorganisms. The study aimed to investigate the utilization of cocoa bean shells for the production of silver nanoparticles through green synthesis, besides its characterization and evaluation against foodborne pathogens. To this end, total phenolic compounds, individual bioactive compounds, and antioxidant activity were evaluated in the aqueous extract of the cocoa bean shell. In addition, the size and stability of the silver nanoparticles were investigated (zeta potential and dynamic light scattering), morphology (scanning electron microscopy), chemical composition (mid-infrared spectroscopy), and their effectiveness against Escherichia coli (ATCC 25922), Listeria monocytogenes (ATCC 19117), Staphylococcus aureus (ATCC 22923), Salmonella enteritidis (S64), Cronobacter sakazakii (ATCC 29004), and Klebsiella pneumoniae (ATCC 18883). The extract was rich in reducing agents and efficiently produced AgNPs with high surface area (74.51 ± 0.38 nm) and stability (− 17.97 ± 0.12 mV). The nanoparticles were also found to be effective against all tested pathogens, demonstrating the potential of agro-industrial waste to produce AgNPs for various industrial applications. [ABSTRACT FROM AUTHOR]

Bacteriocins are antimicrobial peptides produced by bacteria to prevent the growth of pathogens. Combining bacteriocins with metal nanoparticles, like silver nanoparticles (AgNPs), has developed into a viable strategy to get over bacteriocin limitations. In this study, bacteriocin BacZY05 was extracted from Bacillus subtilis ZY05 and purified using various techniques. The resulting purified bacteriocin was then combined with silver nanoparticles to form bacteriocin silver nanoconjugates (BacZY05-AgNPs). The physicochemical properties of the BacZY05-AgNPs were characterized using various analytical techniques. The mean diameter of the synthesized AgNPs was approximately 20–60 nm with an oval or spherical shape. The antimicrobial activity of the BacZY05-AgNPs was evaluated against several indicator strains by their zone of inhibition (ZOI), using the agar well diffusion method. Compared to bacteriocin (ZOI- 13 to 20 mm) and AgNPs (ZOI- 10–22 mm) alone, the antibacterial activity data demonstrated a 1.3-1.5-fold increase in the activity of bacteriocin-nanoconjugates (ZOI- 22 to 26 mm). For Staphylococcus aureus MTCC3103 and Klebsiella pneumoniae MTCC109, BacZY05-capped AgNPs exhibited the lowest minimum inhibitory concentration (MIC), measuring 10.93 µg/mL. For Salmonella typhi NCIM2501, the MIC was 28.75 µg/mL. The highest MIC value was 57.5 µg/mL for Escherichia coli DH5α and Vibrio cholerae MTCC3909. With BacZY05-capped AgNPs, the lowest minimum bactericidal concentration (MBC) of 28.75 µg/mL was observed for Staphylococcus aureus MTCC31003. In the cases of Salmonella typhi NCIM2501 and Klebsiella pneumoniae MTCC109 concentration was 57.5 µg/mL. Vibrio cholerae MTCC3909 and Escherichia coli DH5α had the highest MBC values at 115 µg/mL. [ABSTRACT FROM AUTHOR]

Modification of local bamboo‐based catalytic activated carbon with metallic Ag can produce mesopore and micropore types, with a mesopore content of 86%. One of the best ways to reduce formaldehyde concentrations is through catalytic adsorption. In combination with Ag nanoparticle catalyst, formaldehyde adsorption capacity is improved. Adsorption and oxidation reaction experiments are performed in a fixed bed column (di = 10 mm, length = 90 mm). The increase in formaldehyde adsorption associated with the reaction rate of formaldehyde oxidation by metallic Ag is 51 g/mmol. The oxidation reaction of Ag nanoparticles is a bimolecular reaction based on the Langmuir–Hinshelwood mechanism. Formaldehyde can be reduced by 59% and 41% through the role of adsorption and support of catalytic oxidation, respectively. Additionally, harmless gases such as CO2 and H2O are produced within the column. [ABSTRACT FROM AUTHOR]

Efficient cooperative lubrication can be achieved via the introduction of core-shell structure lubricant additives with hard core and soft shell, for obtaining the expected anti-wear performance from the structural changes in the friction process. In this study, C@Ag microspheres with a core-shell structure were prepared by the redox method with carbon spheres as the core and Ag nanoparticles as the shell. Their tribological behaviors as base oil (G1830) additive with different concentrations were investigated in detail. Compared with base oil, the addition of C@Ag particles at 0.5 wt% can reduce the coefficient of friction (COF) and wear volume (Wv) up to 15.5% and 88%, respectively. More importantly, C@Ag particles provide superior lubrication performance to single additive (like carbon sphere (CS) and Ag nanoparticle). C@Ag core-shell particles contribute to the formation of tribo-film by melt bonding of flexible Ag and carbon sphere (CS) toward excellent self-repair performance and high-efficiency lubrication. Hence, core-shell structural nanoparticles with hard-core and soft-shell hold bright future for high-performance lubrication application. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) are widely used in antimicrobial applications. However, its easy aggregation and rapid loss hinder the effective antifouling. To address this issue, a novel stimuli-responsive antibacterial nanocomposite (Ag@SP-MSN) was developed based on spiropyran covalently conjugated mesoporous silica nanoparticles (284.6 nm) and AgNPs (27.1 nm) via strong electrostatic attraction. Both transmission electron microscopy (TEM) and atomic force microscopy (AFM) images proved the successful modification of AgNPs onto SP-MSN. The light-induced maximum loading amount towards AgNPs was calculated to be 95.0 wt.% after ultraviolet irradiation, while the amount of AgNPs released from Ag@SP-MSN was 94.4 wt.% under visible light in the aid of ammonia (0.1%, v/v). Upon cycled light irradiation, Ag@SP-MSN could recover 84.5 wt.% of AgNPs even after four cycles. The proposed Ag@SP-MSN exhibited better antibacterial activity against both E. coli and S. aureus than Ag@MSN under visible light illumination, indicating the efficient photo-responsive isomerization of spiropyran. Furthermore, the Ag@SP-MSN embedded gel demonstrated outstanding antifouling ability even after 21 days when compared to AgNPs gel. The long-term photo-controllable antifouling property proved the excellent reversible absorption and release of Ag@SP-MSN towards AgNPs. This work provides new insights into the safe utilization of nanomaterials, offering promising advancements to meet clinical antibacterial requirements. [ABSTRACT FROM AUTHOR]

Understanding the structural stability of nanomaterials such as nanowires is imperative for their practical applications. Here, using single-shot ultrafast transmission electron microscopy, we captured the Plateau-Rayleigh instability behavior of silver nanowires decomposing into silver nanoparticles upon laser irradiation on nanosecond time scales. We found that this dynamic process can be accelerated by a factor of 10 through increasing the peak laser fluence from 6.03 to 14.60 mJ/cm2. Moreover, by comparing the laser fluence required to initiate the Plateau-Rayleigh instability in silver nanowires on carbon and Formvar membranes, it was found that the main driving force for the Plateau-Rayleigh instability in this study was substrate heating. Finite element analysis and molecular dynamics simulations are also applied to estimate the temperature jump of the nanowires and atomistic behavior, respectively. In addition, the complex motions of silver nanowires under laser irradiation were systematically investigated by combining the results of ultrafast transmission electron microscopy with scanning electron microscopy characterizations and were determined to be related to nanowire-membrane interactions or pre-existing stresses on the nanowires, which in turn demonstrated the potential of ultrafast transmission electron microscopy for the characterization of nanomaterials and devices under extreme conditions. [ABSTRACT FROM AUTHOR]

Polyhydroxyurethane (PHU) with free secondary amine groups was synthesized by reacting poly(ethylene glycol)bis-cyclic carbonate with triethylenetetramine. PHU was mixed with varying amounts of gelatin (GE) and crosslinked by reacting them with either poly(ethylene glycol)glycidyl ether (PEGDE) or 1,4-butanediol diglycidyl ether (BDDE). The tensile strength and fluid handling capacity of the monolayer films obtained from different formulations of PHU, GE, PEGDE, or BDDE were evaluated. To further improve the tensile strength of dressings via increasing the crosslinking of the networks, varying amounts of epoxidized graphene oxide (EGO) were utilized as an auxiliary crosslinking agent. The improved tensile strength of up to 140% was recorded for these samples. Additionally, the membranes containing EGO were able to absorb near-infrared light. The resulting hyperthermia effect (increasing temperature up to about 63 within 15 min) could efficiently kill bacteria (100% killing). The free secondary amine groups on the PHU backbone also reduced the silver ions loaded into the dressings, and resulting silver nanoparticles (Ag NPs) showed acceptable antibacterial activity against E.coli (53% killing) and S.aureus (78% killing). It was also found that the antibacterial activity of AgNPs-containing samples was further improved after incorporating EGO due to the knife-killing effect of EGO nanoplates. [ABSTRACT FROM AUTHOR]

Developing wound dressings with healing properties is a crucial requirement, especially in developing countries. In this research work, chitosan is extracted from Monomia gladiator crab shells for the first time to fabricate a novel wound dressing. The prepared chitosan (CS) is blended with silk sericin (SS), polyvinyl alcohol (PVA), and silver nanoparticles (AgNPs) in three different ratios of PVA:CS:SS (100:0:0), PVA:CS:SS (80:10:10) – AgNPs, and PVA:CS:SS (50:25:25) – AgNPs to produce nanofibers. The developed nanofibers were analyzed under a scanning electron microscope (SEM), tensile testing, and antibacterial activity to study their fiber size, tensile strength, and bactericidal properties, respectively. The cell viability test against L929 cells demonstrates that the prepared wound dressing is noncytotoxic and facilitates cell proliferation. In vivo research on a full‐thickness excision wound model states that the incorporation of SS, CS, and AgNPs into the PVA introduces a novel multifunctional advancement in wound dressing, offering versatile benefits by promoting reepithelialization and collagen deposition. In summary, PVA:CS:SS(50:25:25)‐AgNPs can serve as an excellent wound dressing. Highlights: CS extracted from Monomia gladiator crab shells.The extracted CS is blended with SS, PVA and AgNPs to fabricate nanofibers.The inclusion of CS and SS exhibited good tensile strength and antibacterial activity.PVA:CS:SS(50:25:25)‐AgNPs served as an excellent wound dressing. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) are among the most produced nanomaterials in the world and are incorporated into several products due to their biocide and physicochemical properties. Since freshwater bodies are AgNPs main final sink, several consequences for biota are expected to occur. With the hypothesis that AgNPs can interact with environmental factors, we analyzed their ecotoxicity in combination with humic acids and algae. In addition to the specific AgNPs behavior in the media, we analyzed the mortality, growth, and phototactic behavior of Chydorus eurynotus (Cladocera) as response variables. While algae promoted Ag+ release, humic acids reduced it by adsorption, and their combination resulted in an intermediated Ag+ release. AgNPs affected C. eurynotus survival and growth, but algae and humic acids reduced AgNPs lethality, especially when combined. The humic acids mitigated AgNP effects in C. eurynotus growth, and both factors improved its phototactic behavior. It is essential to deepen the study of the isolated and combined influences of environmental factors on the ecotoxicity of nanoparticles to achieve accurate predictions under realistic exposure scenarios. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the antibacterial effect of silver nanoparticles (AgNPs) against Enterococcus faecalis and compare it with different irrigation solutions. This study was performed using 64 dentin blocks. E. faecalis suspension was dispensed to each sample and incubated under anaerobic conditions at 37°C throughout 21 days. After the inoculation period, the following solutions were added to each group and kept for 5 min: Group 1, 5.25% sodium hypochlorite (NaOCl); Group 2, 2.5% NaOCl; Group 3, 1% NaOCl; Group 4, 2% chlorhexidine (CHX); Group 5, 200 ppm hypochlorous acid (HOCl); and Group 6, AgNPs. The samples of positive control were treated with sterile saline. Biofilm viability assay was performed using the LIVE/DEAD BacLight Bacterial Viability Kit. Samples were examined using confocal laser scanning microscopy, respectively. There was no significant difference between the 5.25% NaOCl, 2.5% NaOCl, and 1%NaOCl groups (p >.05). However, these groups showed statistically higher antibacterial activity than the 2% CHX, 200 ppm HOCl, and AgNP groups. Also, 2% CHX showed greater percentage of dead cells compared with the AgNP and HOCl groups. While AgNPs group showed lower dead cell rate than all NaOCl groups and 2% CHX, it caused higher dead cells than 200 ppm HOCl group. The 200 ppm HOCl group showed the lowest percentage of dead cells (p <.05) Although the antibacterial effect of AgNPs is not as high as NaOCl and CHX, it has considerable bactericidal activity against E. faecalis and can be improved by further studies. Research Highlights: New antimicrobial approaches for root canal irrigation.Antimicrobial effect of silver nanoparticles against E. faecalis.Elimination of the biofilm layer for the success of endodontic treatment. [ABSTRACT FROM AUTHOR]

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Introduction: Soybean is a rich source of bioactive components with good nutritional support and is easily available. In the treatment of cancer, green synthesis of silver nanoparticles (AgNPs) from plant-based samples has gained attentions due to its potency and feasibility. In the present study, using soybean extracts (GM), silver nanoparticles are synthesized and analyzed for their anticancer potency. Methods: The synthesized GM-AgNPs were characterized via UV-Vis spectroscopy, Fourier transform-infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray (EDX) techniques for further analysis. Antibacterial activity was evaluated using the disc method and anti-hemolysis activity using the in vitro method, followed by anticancer property evaluation by cytotoxicity, cell migration, apoptosis, and cell cycle. Results and discussion: Our results showed that the synthesized GM-AgNPs were spiral-shaped with a size range of 5-50 nm. The antibacterial activity against Staphylococcus aureus and Klebsiella pneumoniae showed the maximum zone of inhibition at 250 ^ig/mL in comparison with gentamicin. On exploring the anti-hemolysis efficiency, at 200 pg/mL, GM-AgNPs showed no hemolysis in comparison to the extract which showed 40% hemolysis. On analysis of GM-AgNPs against the breast cancer cell line, the nanoparticles displayed the IC50 value of 74.04 pg/mL. Furthermore, at the IC50 concentration, cancer cell migration was reduced. The mechanism of action of GM-AgNPs confirmed the initiation of apoptosis and cell cycle arrest in the sub-G0/G1 (growth phase) phase by 48.19%. In gene expression and protein expression analyses, Bax and Bcl-2 were altered to those of normal physiology. [ABSTRACT FROM AUTHOR]

Re-designing existing nano-silver technologies to optimize efficacy and sustainability has a tangible impact on preventing infections and limiting the spread of pathogenic microorganisms. Advancements in manufacturing processes could lead to more cost-effective and scalable production methods, making nano-silver-based antimicrobial products more accessible in various applications, such as medical devices, textiles, and water purification systems. In this paper, we present a new, versatile, and eco-friendly one-pot process for preparing silver nanoparticles (AgNPs) at room temperature by using a quaternary ammonium salt of hydroxyethyl cellulose (HEC), a green ingredient, acting as a capping and reducing agent. The resulting nano-hybrid phase, AgHEC, consists of AgNPs embedded into a hydrogel matrix with a tunable viscosity depending on the conversion grade, from ions to nanoparticles, and on the pH. To investigate the synthesis kinetics, we monitored the reaction progress within the first 24 h by analyzing the obtained NPs in terms of particle size (dynamic light scattering (DLS), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM)), Z-potential (ELS), surface plasmon resonance (UV-VIS), crystallographic phase (XRD), viscosity, and reaction yield (inductively coupled plasma-optical emission spectrometry (ICP-OES)). To explore the design space associated with AgHEC synthesis, we prepared a set of sample variants by changing two independent key parameters that affect nucleation and growth steps, thereby impacting the physicochemical properties and the investigated antimicrobial activity. One of the identified design alternatives pointed out an improved antimicrobial activity in the suspension, which was confirmed after application as a coating on nonwoven cellulose fabrics. This enhancement was attributed to a lower particle size distribution and a positive synergistic effect with the HEC matrix. [ABSTRACT FROM AUTHOR]

ABSTRACT In this study, it is aimed to increase the wear and fatigue performance of aluminium‐based sliding bearing material by using silver nanoparticles (AgNPs) added lubricant and shot‐peening process. The main purpose is to minimise the wear of the bearing material by penetrating AgNPs added lubricants into the rough surfaces formed by shot peening. Almen intensity, coverage and shot size parameters in the shot‐peening process were analysed in terms of hardness, surface roughness and fatigue strength. The shot‐peened aluminium bronze was subjected to wear experiments under dry, pure water and AgNPs added lubricant conditions. The wear test results were analysed in terms of friction coefficient, wear volume and surface roughness parameters, and the interaction of lubricant and shot‐peening parameters was evaluated. According to the results of the shot‐peening experiments, the Almen intensity was the most effective parameter in terms of hardness and surface roughness (91.62%). It was concluded that the hardness value was 8% higher at high Almen (12–14A) intensity compared with low Almen intensities, and the shot‐peening process could increase the fatigue strength by ~21 times. According to the wear tests, the most effective parameters were 4–6 Almen intensity and AgNP‐added lubricant. [ABSTRACT FROM AUTHOR]

Surface‐enhanced Raman scattering (SERS) imaging technology faces significant technical bottlenecks in ensuring balanced spatial resolution, preventing image bias induced by substrate heterogeneity, accurate quantitative analysis, and substrate preparation that enhances Raman signal strength on a global scale. To systematically solve these problems, artificial intelligence techniques are applied to analyze the signals of pesticides based on 3D and dynamic SERS imaging. Utilizing perovskite/silver nanoparticles composites (CaTiO3/Ag@BONPs) as enhanced substrates, enabling it not only to cleanse pesticide residues from the surface to pulp of fruits and vegetables, but also to investigate the penetration dynamics of an array of pesticides (chlorpyrifos, thiabendazole, thiram, and acetamiprid). The findings challenge existing paradigms, unveiling a previously unnoticed weakening process during pesticide invasion and revealing the surprising permeability of non‐systemic pesticides. Of particular note is easy to overlook that the combined application of pesticides can inadvertently intensify their invasive capacity due to pesticide interactions. The innovative study delves into the realm of pesticide penetration, propelling a paradigm shift in the understanding of food safety. Meanwhile, this strategy provides strong support for the cutting‐edge application of SERS imaging technology and also brings valuable reference and enlightenment for researchers in related fields. [ABSTRACT FROM AUTHOR]

The chemistry of silver nanoparticles incorporating a covalently bound complexing agent is dealt with in this paper. The particles have been obtained by the direct reaction of silver ions with the ranelate species obtained from an old antiosteoporotic drug. The ranelate ion exhibits a thiophene structure encompassing a cyanonitrile and two carboxylic groups, in addition to a chelating nitrilebis(diacetate) moiety. Through metal substitution and redox processes involving decarboxylation at the C5-thiophene position, chocolate-brown silver-ranelate nanoparticles (AgNP@Ran) have been generated. As corroborated by the XPS and Raman data, the nanoparticles are strongly stabilized by Ag–C bonds and are inert to substitution. This allows the exploration of their coordination chemistry in the presence of transition and rare earth metal ions, under the influence of plasmonics and the SERS effect. Due to the small nanoparticle size and the high energy spectral band (415 nm), although no significant SERS response has been detected in the excitation range of 488–785 nm, a gradual enhancement has been observed over time, at 488 nm. This observation was ascribed to the laser-induced aggregation of the silver nanoparticles, leading to the SERS effect. The silver ranelate nanoparticles exhibited dramatic changes in their optical and SERS spectra in the presence of transition metal ions such as Cu(II), forming stable complexes in aqueous solution. In the case of Tb3+ ions, instead of the SERS effect, an enhanced fluorescence emission was observed, involving energy transfer from the ranelate ligand to the terbium 4f levels. In this way, silver ranelate nanoparticles make interesting optical sensors for metal ions and can be useful as fluorescent/plasmonic markers for chemical and biological systems. [ABSTRACT FROM AUTHOR]