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[Display omitted] Novel two-dimensional MXene with unique optical and electrical properties has become a new focus in the field of sensing. In particular, their metallic conductivity, good biocompatibility and high anchoring ability to biomaterials make them attractive candidates. Despite such remarkable properties, there are certain limitations, such as low oxidative stability. MXene-Metal interactions are an effective strategy to maintain the long-term stability of MXene, while also improving the electrochemical activity and optical properties. Herein, a series of MXene/Ag nanocomposites including Ti 3 C 2 /Ag, Nb 2 C/Ag and V 2 C/Ag were designed based on the surface chemistry characteristics of MXene, where MXene served as the substrate for in-situ growth of silver nanoparticles via self-reduction of Ag(NH 3) 2 +. The results showed that V 2 C MXene has the strongest self-reducing ability due to its multiple variable valence states, larger interlayer space and more reactive groups. Moreover, V 2 C/Ag exhibited unexpected oxygen reduction reaction catalytic activity and photothermal performance. In view of which, an electrochemiluminescence-photothermal (ECL-photothermal) immunosensor was developed using V 2 C/Ag as ECL anchor and photothermal reagent for ultrasensitive detection of Lipolysis stimulated lipoprotein receptor. This work not only provides a simple and effective synthesis method of MXene supported metal nanocomposites, but also provides more inspirations for exploring the efficient biosensing strategies. [ABSTRACT FROM AUTHOR]

A self-standable, transparent, self-adhesive, bending resistant and highly adaptive SERS substrate has been fabricated by depositing Ag nanoparticles (AgNPs) on CdS nanowires (CdSNWs) embedded in a specially prepared nanofilm matrix, and further used for the in-situ, at real-time, sensitive and selective detection of urea in human sweat and plant leaves. [Display omitted] Wearable SERS substrates have gained substantial attention for health monitoring and other applications. Current designs often rely on conventional polymer substrates, leading to discomfort and complexity due to the need of additional adhesive layers. To address the issues, we fabricate a flexible, uniform, ultrathin, transparent and porous SERS substrate via depositing Ag nanoparticles (AgNPs) onto the CdS nanowires (CdSNWs) grown on the surface of a prepared nanofilm (AgNPs-CdSNWs/nanofilm). Unlike the wearable SERS substrates reported in literature, the one presented in this work is self-adhesive to a variety of surfaces, which simplifies structure, enhances comfort and improves performance. Importantly, the new SERS substrate as developed is highly stable and reusable. Artificial sample tests revealed that the substrate showed a great enhancement factor (EF) of 4.2 × 107 and achieved a remarkable detection limit (DL) of 1.0 × 10−14 M for rhodamine 6G (R6G), which are among the highest records observed in wearable SERS substrates reported in literature. Moreover, the substrate enables at real-time and in-situ reliable monitoring of urea dynamics in human sweat and plant leaves, indicating its applicability for health analysis and in precision agriculture. [ABSTRACT FROM AUTHOR]

[Display omitted] Efficient utilizing CO 2 is crucial approaches in achieving carbon neutralization. One of the challenges lies in the in-situ conversion of low concentration CO 2 found in waste gases. This study introduces a novel heterogeneous catalyst known as silver nanoparticles in porous N -heterocyclic carbene polymer (Ag@POP-NL-3). The catalyst is synthesized via a streamlined pre-coordination method. Ag@POP-NL-3 exhibits uniform distribution of silver nanoparticles, a porous structure and nitrogen activation groups. It demonstrates high efficiency and selectivity in absorbing and activating CO 2 and enabling the conversion of low concentration CO 2 (30 vol%) from lime kiln waste gas into cyclic carbonate under mild conditions. This catalytic system achieves both CO 2 capture and resource utilization of CO 2 simultaneously, effectively fixing low-concentration CO 2 from waste gases into C 2+ valuable chemicals. This approach elegantly addresses two goals in one solution. [ABSTRACT FROM AUTHOR]

The antimicrobial property of core-shell silver nanoparticles (Ag@mSiO 2) is better than that of yolk-shell silver nanoparticles (Ag@YSiO 2), which plays a protective role in silk cultural relics without interference. [Display omitted] Silver nanoparticles coated with organic-inorganic hybrid silica or inorganic silica have antimicrobial ability, and the coating can also effectively improve the dispersion and stability of the particles. The slow release of silver ions (Ag+) can improve the antimicrobial activity of silver nanoparticles. The synthesized nanoparticles are light yellow, which does not affect the look and feel of the silk cultural relics and meets the requirements of the principle of minimum interference. Two kinds of silver-based nanoparticles were synthesized: silver core-shell nanoparticle (Ag@mSiO 2) and silver yolk-shell nanoparticle (Ag@YSiO 2). The morphology, surface properties and Ag+ release efficiency of two nanoparticles were characterized. The antimicrobial effects of two nanoparticles on Aspergillus niger (A. niger) and Penicillium citrinum (P. citrinum) were compared. Both of Ag@mSiO 2 and Ag@YSiO 2 had uniform size and good stability. Two nanoparticles had pore structure and silver nanocore, which provided the basis for the dissolution and exchange of Ag+. Because more silver ions were released, Ag@mSiO 2 had higher antimicrobial activity than Ag@YSiO 2 for A. niger and P. citrinum. For various silk samples, Ag@mSiO 2 exhibited excellent antimicrobial properties. Meanwhile, there was little change in the color and tearing strength of Ag@mSiO 2 coated silk. [ABSTRACT FROM AUTHOR]

[Display omitted] Pseudomonas aeruginosa bacteria originate severe infections in hospitalized patients and those with chronic debilitating diseases leading to increased morbidity and mortality, longer hospitalization and huge financial burden to the healthcare system. The clinical relevance of P. aeruginosa infections is increased by the capability of this bacterium to grow in biofilms and develop multidrug resistant mechanisms that preclude conventional antibiotic treatments. Herein, we engineered novel multimodal nanocomposites that integrate in the same entity antimicrobial silver nanoparticles (NPs), the intrinsically antimicrobial, but biocompatible biopolymer chitosan, and the anti-infective quorum quenching enzyme acylase I. Acylase present in the NPs specifically degraded the signal molecules governing bacterial cell-to-cell communication and inhibited by ∼ 55 % P. aeruginosa biofilm formation, while the silver/chitosan template altered the integrity of bacterial membrane, leading to complete eradication of planktonic bacteria. The innovative combination of multiple bacteria targeting modalities resulted in 100-fold synergistic enhancement of the antimicrobial efficacy of the nanocomposite at lower and non-hazardous towards human skin cells concentrations, compared to the silver/chitosan NPs alone. [ABSTRACT FROM AUTHOR]

Viruses can be involved in respiratory disorders in horses, with limited therapeutic options. Citrate-complexed silver nanoparticles (C–AgNP) have shown bactericidal properties after in vitro nebulization. The aim of the present study was to assess the virucidal activity of C–AgNP after in vitro instillation or nebulization on equine herpesvirus-1 (EHV-1) and murine norovirus (MNV), the latter used as surrogate for small non-enveloped viruses. Both viruses were instilled or nebulized with C–AgNP of increasing concentrations, and titres were determined via TCID 50 method. We demonstrated efficient inactivation of enveloped EHV-1 following instillation and nebulization of C–AgNP (infectivity losses of ≥ three orders of magnitude). While tenacious MNV was inactivated via 2000 ppm C–AgNP instillation, nebulized C–AgNP did not lead to reduction in MNV titres. Nebulization of C–AgNP may represent a novel virucidal therapeutic approach in horses. Further investigations are needed to assess its safety and effective concentrations for in vivo use. • Instilled citrate-complexed silver nanoparticles (C–AgNP) inactivate equine herpesvirus-1 (EHV-1) in vitro. • C–AgNP preserve their virucidal activity after in vitro nebulization on EHV-1. • Instilled C–AgNP inactivate small, non-enveloped murine norovirus (MNV) in vitro. • C–AgNP show some in vitro virucidal activity on MNV, while response seems related to concentration. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nanocomposites of ZIF-8, carbon nanodots and silver nanoparticles are prepared. • A novel fluorescent sensing strategy is developed for the detection of H 2 O 2 and glucose based on AgNP-CD-ZIF-8. • Excellent analytical performances are achieved, which might inspire future studies on MOF assembly. In this study, a novel fluorescent biosensor is developed for the detection of H 2 O 2 and glucose based on Zeolitic Imidazolate Framework-8 (ZIF-8) nanocomposites. ZIF-8 encapsulating carbon nanodot (CD) exhibits bright fluorescence emission. After further loading of AgNP, the fluorescence is quenched, which is mainly based on the excited electron transfer from CD to AgNP. Besides, the excitation wavelength of CD falls within the adsorption range of AgNP, which leads to efficient inhibition of the excitation energy. The as-prepared AgNP-CD-ZIF-8 nanocomposites can be utilized as a highly sensitive platform for the analysis of H 2 O 2 and glucose. In the presence of glucose, H 2 O 2 can be generated by the catalysis of glucose oxidase (GOD), which induces the etching of AgNP and subsequent recovery of CD-ZIF-8 fluorescence. This "turn on" biosensor can be applied for facile and convenient quantification of H 2 O 2. It can also be further extended to detect glucose in real samples after combining specific catalytic effect of GOD. The analytical performances are excellent, which demonstrates great potential for practical utility. [ABSTRACT FROM AUTHOR]

Using extracts from herbs for silver nanoparticle synthesis is attracting attention for its anticancer activity. Ardisia gigantifolia is a herb used in traditional Chinese medicine for treating stomach ailments, and some compounds isolated from this plant exhibit the inhibitory activity against different cancer cells. However, the synthesis of silver nanoparticle using extract of Ardisia gigantiflia leaves and their anti-cancer activity was not reported. In this report, the green synthesized silver nanoparticles using Ardisia gigantiflia extract (Arg-AgNPs) has average diameter of 6 nm with functional groups including O–H, C–H, and C O founded on the surface of these nanoparticles. The viability assays results revealed Arg-AgNPs reduced gastric cancer cell proliferation in a dose-dependent manner, with IC 50 values of 1.37 and 0.65 μg/mL for AGS cells and 1.03 and 0.96 μg/mL for MKN45 cells. Arg-AgNPs caused cell cycle arrest at the G0/G1 phase and suppressed cell migration. Additionally, Arg-AgNPs significantly increased the percentage of senescent cells and promoted overproduction of reactive oxygen species (ROS) compared to the control. Thus, this study indicates that Arg-AgNPs can be considered as a promising candidate against human gastric cancer cells. • Arg-AgNPs were characterized by UV-Vis, XRD, TEM and FTIR. • Arg-AgNPs reduce cell viability and cause cell cycle arrest at G0/G1 phase in gastric cancer. • Arg-AgNPs reduce cell migration ability and induce cellular senescence in gastric cancer. • Arg-AgNPs promote overproduction of ROS in gastric cancer. [ABSTRACT FROM AUTHOR]

Nanotechnology has become the focus of scientific research due to its widespread and effective use. Silver nanoparticles (AgNPs) were produced utilizing Stachys spectabilis, and their antioxidant effect and catalytic degradation of methylene blue were investigated. The structure of ss-AgNPs was clarified by spectroscopy. FTIR demonstrated the possible functional group responsible for reducing agents. The absorption at 498 nm in the UV–Vis measurement verified the nanoparticle structure. XRD measurement demonstrated the nanoparticles to be face-centered cubic crystalline structures. TEM image proved the nanoparticles as spherical, and the size was determined as 10.8 nm. The intense signals at 2.8–3.5 keV in EDX confirmed desired product. The observation of zeta potential at −12.8 mV indicated the stability of nanoparticles. The nanoparticles can degrade the methylene blue with 54% at 40 h. The antioxidant effect of extract and nanoparticles was performed by ABTS radical cation, DPPH free radical scavenging, and FRAP assay. Nanoparticles revealed excellent ABTS activity (4.42 ± 0.10) in comparison to the standard BHT (7.12 ± 0.10). ss-AgNPs may be a promising agent for the pharmacy. • Silver nanoparticles were synthesized using Stachys spectabilis leaves. • UV–Vis, FTIR, XRD, TEM, EDX were used for elucidation of nanoparticles. • Nanoparticles displayed the outstanding antioxidant activity. • Nanoparticles synthesized from this plant can be used for clean technology. • Nanoparticles could be a promising agent for pharmaceutical industry. [ABSTRACT FROM AUTHOR]

The bacterial cellulose membrane (CM) is a promising biomaterial due to its easy applicability and moist environment. Moreover, nanoscale silver compounds (AgNO 3) are synthesized and incorporated into CMs to provide these biomaterials with antimicrobial activity for wound healing. This study aimed to evaluate the cell viability of CM incorporated with nanoscale silver compounds, determine the minimum inhibitory concentration (MIC) for Escherichia coli and Staphylococcus aureus , and its use on in vivo skin lesions. Wistar rats were divided according to treatment: untreated, CM (cellulose membrane), and AgCM (CM incorporated with silver nanoparticles). The euthanasia was performed on the 2nd, 7th, 14th, and 21st days to assess inflammation (myeloperoxidase-neutrophils, N-acetylglucosaminidase-macrophage, IL-1β, IL-10), oxidative stress (NO-nitric oxide, DCF-H 2 O 2), oxidative damage (carbonyl: membrane's damage; sulfhydryl: membrane's integrity), antioxidants (superoxide dismutase; glutathione), angiogenesis, tissue formation (collagen, TGF-β1, smooth muscle α-actin, small decorin, and biglycan proteoglycans). The use of AgCM did not show toxicity, but antibacterial effect in vitro. Moreover, in vivo, AgCM provided balanced oxidative action, modulated the inflammatory profile due to the reduction of IL-1β level and increase in IL-10 level, in addition to increased angiogenesis and collagen formation. The results suggest the use of silver nanoparticles (AgCM) enhanced the CM properties by providing antibacterial properties, modulation the inflammatory phase, and consequently promotes the healing of skin lesions, which can be used clinically to treat injuries. • Silver nanoparticles (around 15-nm in size) were successfully incorporated into bacterial cellulose membranes. • Bacterial cellulose membrane (BCM) with silver nanoparticles: bacteriostatic property; no cytotoxicity for animal cells. • BCM with silver nanoparticles modulated the inflammatory process and stimulated angiogenesis and collagen formation. • Balanced oxidative stress and antioxidant markers by treating wounds with BCM incorporated with silver nanoparticles. [ABSTRACT FROM AUTHOR]

[Display omitted] Autonomous self-propelled micromachines based on semiconductors are at the forefront of environmental pollutants degradation research to palliate the effects of the contamination arising from the constant manufacturing of new products. Nonetheless, testing these micromotors with real-life products is almost an unexplored field, limiting the degradation of pollutants to single-component aqueous solutions or suspensions at the laboratory scale, which hinders the translation of these micromachines into useful systems. Herein, Ag 3 VO 4 has been devised as a micromotor by an asymmetric deposition of a thin layer of Pt, giving rise to Pt/Ag 3 VO 4 micromotors (Janus particle). Their motion capabilities have been demonstrated under UV light in fuel-free conditions. Their photocatalytic performance at laboratory scale has been confirmed for the degradation of Rhodamine B while, as a first approximation of a real-life application, the degradation of an energy drink has also been tested. During this latter exploration, the Pt/Ag 3 VO 4 micromotors were corroded by the citric acid present in the pollutant, releasing Ag nanoparticles into the media. As a proof of concept, the position of the generated Ag nanoparticles' surface plasmon resonance absorption maximum has been demonstrated to show a dependency on the concentration of citric acid. [ABSTRACT FROM AUTHOR]

[Display omitted] Silver nanoparticles (AgNPs) have found widespread commercial applications due to their unique physical and chemical properties. However, their relatively poor stability remains a main problem. An ideal way to improve the stability of AgNPs is not only to endow colloidal stability to individual nanoparticles but also to protect them from environmental factors that induce their agglomeration, like variation of ionic strength and pH, presence of macromolecules, etc. Mesoporous calcium carbonate vaterite crystals (CaCO 3 vaterite) have recently attracted significant attention as inexpensive and biocompatible carriers for the encapsulation and controlled release of both drugs and nanoparticles. This work aimed to develop an approach to load AgNPs into CaCO 3 vaterite without affecting their properties. We focused on improving the colloidal stability of AgNPs by using different capping agents, and understanding the mechanism behind AgNPs loading and release from CaCO 3 crystals. Various methods were applied to study the AgNPs and CaCO 3 crystals loaded with AgNPs (CaCO 3 /AgNPs hybrids), such as scanning and transmission electron microscopy, X-ray diffraction, infrared and mass spectrometry. The results demonstrated that polyvinylpyrrolidone and positively charged diethylaminoethyl-dextran can effectively keep the colloidal stability of AgNPs during co-precipitation with CaCO 3 crystals. CaCO 3 /AgNPs hybrids composed of up to 4 % weight content of nanoparticles were produced, with the loading mechanism being well-described by the Langmuir adsorption model. In vitro release studies demonstrated a burst release of stable AgNPs at pH 5.0 and a sustained release at pH 7.5 and 9.0. The antibacterial studies showed that these hybrids are effective against Escherichia coli , methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa , three important bacteria responsible for nosocomial infections. The developed approach opens a new way to stabilise, protect, store and release AgNPs in a controlled manner for their use as antimicrobial agents. [ABSTRACT FROM AUTHOR]

[Display omitted] Flexible pressure sensors have received tremendous attention for various wearable applications. However, it remains a critical challenge to develop a flexible pressure sensor with excellent sensitivity performances and multiple advantageous properties. Herein, a high-performance flexible piezoresistive pressure sensor PMIA@PDA@Ag was developed, which sensitive component is consisted of Ag nanoparticles decorated polydopamine (PDA)-modified meta -aramid (poly(m -phenylene isophthalamide), PMIA) nanofibrous membrane. The PMIA@PDA@Ag pressure sensor shows excellent mechanical, thermal insulation, antibacterial and breathable properties, as well as remarkable sensing performances including high sensitivity, wide detectable pressure range, rapid response speed and good cyclic durability. In addition, it also shows great sensing performances in monitoring various human behaviors in real-time, including large-scale motions and subtle physiological signals. [ABSTRACT FROM AUTHOR]

[Display omitted] The size of silver nanoparticles (Ag NPs) and loading amount of Ag NPs onto their substrate/carrier are two key factors for their efficient applications. Herein, we present a facile method for in situ synthesizing ultrafine and highly loaded Ag NPs on the surface of tannin-coated catechol-formaldehyde resin (TA-CFR) nanospheres. TA-CFR nanospheres act as green and highly efficient reducing agents for converting silver ions (Ag+) into Ag NPs, and the size of resultant Ag NPs is only ∼ 7.5 nm, and the Ag NPs loading capacity of TA-CFR is as high as 61.5 wt%, both of which contribute to the very high specific surface area of Ag NPs. Consequently, the as-synthesized TA-CFR@Ag composites show high catalytic performance, and the catalytic rate for the reduction of 4-nitrophenol is almost 10 times higher than that of the control. Meanwhile, TA-CFR@Ag composites also possess high antibacterial activity, efficiently inhibiting the growth of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Furthermore, tannin coating (thickness: ∼ 15 nm) minimizes the aggregation of Ag NPs, and enhances the reusability and stability of resultant Ag NPs, because of their high surface charges (the zeta potential is up to −65.5 ± 1.9 mV) and strong coordination capability with Ag NPs. This work provides a new frontier to develop multifunctional nanomaterials focusing on the green catalyst synthesis and environmental-remedy applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ag or Au nanoparticles were deposited on ZnIn 2 S 4 via in situ sulfur vacancy induced metal precursor reduction approach. • ZIS/Ag(Au)/FeTCPP system was applied for CO 2 photoreduction. • Ag function as a promoter for interfacial charge transfer from ZnIn 2 S 4 to the FeTCPP and greatly facilitates the CO production. • The loaded Au is beneficial to H 2 generation. The construction of hybrid catalysts composed of inorganic semiconductors and molecular catalysts shows great potential for achieving high photocatalytic carbon dioxide (CO 2) conversion efficiency. In this study, ZnIn 2 S 4 was first synthesized via a solvothermal route. Gold (Au) and silver (Ag) nanoparticles were then deposited on ZnIn 2 S 4 via the reduction of noble metal precursor by sulfur vacancy defects. The obtained composite was further combined with tetra(4-carboxyphenyl)porphyrin iron(III) chloride (FeTCPP) molecular catalyst for efficient photocatalytic CO 2 conversion. The roles of different noble metal nanoparticles in charge separation and interfacial electron transfer have been comprehensively studied. The photocatalytic performance and photoelectrochemical characterizations demonstrate that the introduction of Ag or Au nanoparticles is beneficial for charge separation. More importantly, the presence of Ag nanoparticles plays a crucial role in promoting the interfacial charge transfer between ZnIn 2 S 4 and FeTCPP, whereas, Au nanoparticles function as active sites for the water reduction reaction. [ABSTRACT FROM AUTHOR]

Nanostructured titanium substrates provide inherent antimicrobial activity against drug-resistant fungi and bacteria, mimicking structures on the surface of naturally antimicrobial organisms. The addition of silver nanoparticles onto the nanostructures provides a secondary chemical antimicrobial mechanism and increases the efficacy in the response for both microbial species via low concentrations of silver. [Display omitted] Titanium and its alloys are commonly used implant materials. Once inserted into the body, the interface of the biomaterials is the most likely site for the development of implant-associated infections. Imparting the titanium substrate with high-aspect-ratio nanostructures, which can be uniformly achieved using hydrothermal etching, enables a mechanical contact-killing (mechanoresponsive) mechanism of bacterial and fungal cells. Interaction between cells and the surface shows cellular inactivation via a physical mechanism meaning that careful engineering of the interface is needed to optimse the technology. This mechanism of action is only effective towards surface adsorbed microbes, thus any cells not directly in contact with the substrate will survive and limit the antimicrobial efficacy of the titanium nanostructures. Therefore, we propose that a dual-action mechanoresponsive and chemical–surface approach must be utilised to improve antimicrobial activity. The addition of antimicrobial silver nanoparticles will provide a secondary, chemical mechanism to escalate the microbial response in tandem with the physical puncture of the cells. Hydrothermal etching is used as a facile method to impart variant nanostrucutres on the titanium substrate to increase the antimicrobial response. Increasing concentrations (0.25 M, 0.50 M, 1.0 M, 2.0 M) of sodium hydroxide etching solution were used to provide differing degrees of nanostructured morphology on the surface after 3 h of heating at 150 °C. This produced titanium nanospikes, nanoblades, and nanowires, respectively, as a function of etchant concentration. These substrates then provided an interface for the deposition of silver nanoparticles via a reduction pathway. Methicillin-resistant Staphylococcous aureus (MRSA) and Candida auris (C. auris) were used as model bacteria and fungi, respectively, to test the effectiveness of the nanostructured titanium with and without silver nanoparticles, and the bio-interactions at the interface. The presence of nanostructure increased the bactericidal response of titanium against MRSA from ∼ 10 % on commercially pure titanium to a maximum of ∼ 60 % and increased the fungicidal response from ∼ 10 % to ∼ 70 % in C. auris. Introducing silver nanoparticles increased the microbiocidal response to ∼ 99 % towards both bacteria and fungi. Importantly, this study highlights that nanostructure alone is not sufficient to develop a highly antimicrobial titanium substrate. A dual-action, physical and chemical antimicrobial approach is better suited to produce highly effective antibacterial and antifungal surface technologies. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ag or Au nanoparticles were deposited on ZnIn 2 S 4 via in situ sulfur vacancy induced metal precursor reduction approach. • ZIS/Ag(Au)/FeTCPP system was applied for CO 2 photoreduction. • Ag function as a promoter for interfacial charge transfer from ZnIn 2 S 4 to the FeTCPP and greatly facilitates the CO production. • The loaded Au is beneficial to H 2 generation. The construction of hybrid catalysts composed of inorganic semiconductors and molecular catalysts shows great potential for achieving high photocatalytic carbon dioxide (CO 2) conversion efficiency. In this study, ZnIn 2 S 4 was first synthesized via a solvothermal route. Gold (Au) and silver (Ag) nanoparticles were then deposited on ZnIn 2 S 4 via the reduction of noble metal precursor by sulfur vacancy defects. The obtained composite was further combined with tetra(4-carboxyphenyl)porphyrin iron(III) chloride (FeTCPP) molecular catalyst for efficient photocatalytic CO 2 conversion. The roles of different noble metal nanoparticles in charge separation and interfacial electron transfer have been comprehensively studied. The photocatalytic performance and photoelectrochemical characterizations demonstrate that the introduction of Ag or Au nanoparticles is beneficial for charge separation. More importantly, the presence of Ag nanoparticles plays a crucial role in promoting the interfacial charge transfer between ZnIn 2 S 4 and FeTCPP, whereas, Au nanoparticles function as active sites for the water reduction reaction. [ABSTRACT FROM AUTHOR]

Nanostructured titanium substrates provide inherent antimicrobial activity against drug-resistant fungi and bacteria, mimicking structures on the surface of naturally antimicrobial organisms. The addition of silver nanoparticles onto the nanostructures provides a secondary chemical antimicrobial mechanism and increases the efficacy in the response for both microbial species via low concentrations of silver. [Display omitted] Titanium and its alloys are commonly used implant materials. Once inserted into the body, the interface of the biomaterials is the most likely site for the development of implant-associated infections. Imparting the titanium substrate with high-aspect-ratio nanostructures, which can be uniformly achieved using hydrothermal etching, enables a mechanical contact-killing (mechanoresponsive) mechanism of bacterial and fungal cells. Interaction between cells and the surface shows cellular inactivation via a physical mechanism meaning that careful engineering of the interface is needed to optimse the technology. This mechanism of action is only effective towards surface adsorbed microbes, thus any cells not directly in contact with the substrate will survive and limit the antimicrobial efficacy of the titanium nanostructures. Therefore, we propose that a dual-action mechanoresponsive and chemical–surface approach must be utilised to improve antimicrobial activity. The addition of antimicrobial silver nanoparticles will provide a secondary, chemical mechanism to escalate the microbial response in tandem with the physical puncture of the cells. Hydrothermal etching is used as a facile method to impart variant nanostrucutres on the titanium substrate to increase the antimicrobial response. Increasing concentrations (0.25 M, 0.50 M, 1.0 M, 2.0 M) of sodium hydroxide etching solution were used to provide differing degrees of nanostructured morphology on the surface after 3 h of heating at 150 °C. This produced titanium nanospikes, nanoblades, and nanowires, respectively, as a function of etchant concentration. These substrates then provided an interface for the deposition of silver nanoparticles via a reduction pathway. Methicillin-resistant Staphylococcous aureus (MRSA) and Candida auris (C. auris) were used as model bacteria and fungi, respectively, to test the effectiveness of the nanostructured titanium with and without silver nanoparticles, and the bio-interactions at the interface. The presence of nanostructure increased the bactericidal response of titanium against MRSA from ∼ 10 % on commercially pure titanium to a maximum of ∼ 60 % and increased the fungicidal response from ∼ 10 % to ∼ 70 % in C. auris. Introducing silver nanoparticles increased the microbiocidal response to ∼ 99 % towards both bacteria and fungi. Importantly, this study highlights that nanostructure alone is not sufficient to develop a highly antimicrobial titanium substrate. A dual-action, physical and chemical antimicrobial approach is better suited to produce highly effective antibacterial and antifungal surface technologies. [ABSTRACT FROM AUTHOR]

The synthesized Ag@CoMo-LDH electrode exhibited distinguished electrocatalytic performance compared with most reported advanced OER electrocatalysts. [Display omitted] Modulating electronic resistance properties and enhancing both active site populations and per-site activity are highly desirable for the application of layered double hydroxides (LDHs) in the electrocatalytic oxygen evolution reaction (OER). Herein, a metal-support structure consisting of silver (Ag) nanoparticles supported by MoO 4 2− intercalated Co-LDH (CoMo-LDH) nanocages (Ag@CoMo-LDH) was developed using a sacrificial template method and a subsequent spontaneous strategy. The resultant hybrid was shown to be a highly efficient OER electrocatalyst in alkaline media. The required overpotential of Ag@CoMo-LDH for affording a geometric current density of 10 mA cm−2 is as low as 205 mV, which is not only significantly lower than that of separate CoMo-LDH or Ag nanoparticles but also superior to that of most developed OER electrocatalysts reported recently. The constituents and respective work mechanism of Ag@CoMo-LDH are discussed in detail. The superior performance of Ag@CoMo-LDH is related to the unique construction and the effective and stable heterointerfaces between Ag nanoparticles and CoMo-LDH, which accelerate the electron and mass transfer, provide a large number of new active sites and optimize the activity of the original sites. Impressively, Ag@CoMo-LDH also exhibited promising practical prospect on account of the remarkable cyclic and long-term stability. This finding demonstrates that pointedly integrating multiple strategies into one system is a promising way to construct new LDH-based OER electrocatalysts with synthetically improved performance, providing a promising model for developing advanced electrocatalysts in energy conversion devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • The plating mechanical of metallic Li on carbon microspheres is revealed. • Li-Ag alloy enables high physical plating/stripping and carbon spheres structural are utilized as a Li cage. • Behavior behind the enhanced Li nucleation, plating and stripping is investigated. • Silver-coated N-doped onion-like carbon spheres (Ag@NCS) obtain by simple one-step injection pyrolysis. Lithium metal is considered as a promising anode material for next-generation secondary batteries, owing to its high theoretical specific capacity (3860 mA h g−1). Nevertheless, the practical application of Li in lithium metal batteries (LMBs) is hampered by inhomogeneous Li deposition and irreversible "dead Li", which lead to low coulombic efficiency (CE) and safe hazards. Designing unique lithiophilic structure is an efficient strategy to control Li uniformly plating /stripping. Here, we report the silver (Ag) nanoparticles coated with nitrogen-doped onion-like carbon microspheres (Ag@NCS) as a host to reduce the nucleation overpotential of Li for dendrite-free LBMs. The Ag@NCS were prepared by a simple one-step injection pyrolysis. The lithiophilic Ag is demonstrated to be priority selective deposition of Li in the carbon cage. Meanwhile, the onion-like structure benefits to uniform lithium nucleation and dendrite-free lithium during cycling. Impressively, we successfully captured lithium metal on different hosts at atomic scale, further proving that Ag@NCS can effectively and uniformly deposit Li. Besides, Ag@NCS show a superiorly electrochemical performance with a low nucleation overpotential (∼1 mV), high CE and stable cycling performance (over 400 cycles at 0.5 mA cm−2) compared to the Ag-free onion-like carbon in LMBs. Even under harsh conditions (1 mA cm−2, 4 mA h cm−2), Ag@NCS still present superior cycling stability for more than 150 cycles. Furthermore, a full cell composed of LiFePO 4 cathode exhibits significantly improved voltage hysteresis with low voltage polarization. This work provides a new choice and route for the design and preparation of lithiophilic host materials. [ABSTRACT FROM AUTHOR]

The current protocol describes the green synthesis of silver nanoparticles, which shown photoluminescence, antioxidant, anti-inflammatory, antidiabetic and antibacterial effects utilizing leaf extracts of Muntingia calabura. High-throughput methods (UV–Vis, FTIR, XRD, SEM, EDX and PL) were used to characterize the synthesized Mc- AgNP's. The surface plasmon resonance of Mc -AgNP's was detected around 456 nm using UV–Vis spectroscopy. The different functional groups were revealed from the FTIR spectra. The average crystallite size of Mc- AgNP's was found to be 15.52 nm. The morphology of Mc- AgNP's was found as spherical using SEM. Photoluminescence spectrum showed emission around 445 nm with an excitation of 330 nm. • Green synthesis of silver nanoparticles using aqueous leaf extract of M. calabura. • Characterization of Mc -AgNP's was determined using high-throughput methods by. • UV–Vis spectroscopy, FTIR, XRD, SEM, EDX and PL. • PL spectrum of Mc -AgNP's exhibited emission at 445 nm when it is excited at 330 nm. • Mc -AgNP's exhibited potent antioxidant, anti-inflammatory, antidiabetic and antibacterial activities. [ABSTRACT FROM AUTHOR]

[Display omitted] • Gold and silver nanoparticles have been homogeneously disseminated on BP nanosheet by a light-assisted self-reduction. • Robust SERS chips were successfully developed by assembling BP@Au-Ag nanocomposites into bilayer membrane. • A reliable in-situ recyclable detection strategy has been demonstrated utilizing the tape-mediated SERS chip. • The effective preservation of BP was realized based on the principle of fresh-keeping film. Self-cleaning surface-enhanced Raman scattering (SERS) substrates dependent on versatile two-dimensional semiconductors offer an efficient channel for the sensitive monitoring and timely degradation of hazardous molecules. Herein, a kind of sophisticated SERS-active nanocomposites was developed by incorporating Au-Ag nanoparticles onto black phosphorus (BP) nanosheets via photo-induced self-reduction. Combining the substantial electromagnetic "hot spots" triggered by bimetallic plasma coupling effect and the efficient charge transfer from BP to probe molecules, the proposed nanocomposites featured attractive SERS enhancement, facilitating a limit of detection down to 4.5 × 10−10 M. Attributed to the remarkable restriction of electron-hole recombination stemming from "Schottky contact", the photocatalytic activity of BP was prominently boosted, demonstrating a complete degradation time as short as 65 min. Furthermore, the disgusting instability of BP was considerably hindered by inserting the nanocomposites into various bilayer matrices with diverse hardness and viscosity inspired by cling film principle. Moreover, a significantly elevated collection rate high to 93.1% for in-situ detection was also achieved by the as-manufactured flexible SERS chips based on tape. This study illustrates a clear perspective for the development of versatile BP-based SERS chips which might facilitate sensitive analysis and treatment of perilous contaminants in complicated real-life scenarios. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Ag-modified Bi 2 MoO 6 was obtained for ppb-level NH 3 gas detection. • The highest response (G g /G a = 37.6 to 200 ppb NH 3) under 20% RH. • The synergistic effect of metal–semiconductor junctions and noble metal catalytic. Noble metal-doping and modification are proved effective in improving the gas-response performance of semiconductor sensors. In this study, we developed a promising Bi 2 MoO 6 (BMO)-based gas sensor capable of sensing ppb-level NH 3 at room temperature via introducing silver (Ag). The BMO samples with different Ag doping and modification ratios were successfully formed via one-step solvothermal and glucose reduction techniques, respectively, which could be confirmed by the results of X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HR-TEM) techniques. Compared to bare BMO, the gas-sensing properties of both Ag-doped and Ag surface-modified BMO samples were improved to various extents, respectively. In particular, the 5% Ag-modified BMO sensor with the highest response (G g /G a = 37.6 to 200 ppb NH 3), long-term stability, and low threshold concentration (50 ppb) at 20% RH. Based on the spillover effect and metal–semiconductor junctions of Ag nanoparticles, the enhanced sensing response towards NH 3 can be thoroughly illustrated. Combined with the first-principles calculations, the adsorption energy, density of states, and charge transfer of Ag-modified BMO were further performed to demonstrate the high sensing response and ultra-low detection limit. [ABSTRACT FROM AUTHOR]

[Display omitted] A robust method to prepare silver nanoclusters (AgNCs) inside a methacrylic acid-ethyl acrylate (MAA-EA) nanogel is proposed, where AgNCs were produced within the nanogel scaffold via UV-photoreduction. The impact of UV irradiation time on the formation of AgNCs and their application in biolabeling and antimicrobial properties were examined. The AgNCs formation is described by two stages; (1) Ag n (n = 2–8) nanoclusters formation between 0 and 25 min, and (2) larger silver nanoparticles (AgNPs) formed via aggregation inside the nanogel. The antimicrobial performance depended on the size and concentration of silver ions (Ag+). A maximum inhibitory concentration (MIC) of 1.1 ppm was observed for antimicrobial test with yeast, and a MIC of 11 and 22 ppm was recorded for Escherichia. coli and Staphylococcus aureus respectively. Combining with the green illumination property of AgNCs (emitted at 525 nm) with dead yeast, it could be used for biolabeling. By tuning the size through photoirradiation, the nanogel templated AgNCs is a promising candidate for antimicrobial and biolabeling applications. [ABSTRACT FROM AUTHOR]

Silver nanoparticles with vanadium oxide nanowires were obtained using the vanadium oxide quantum dots as both reductants and stabilizers. It was loaded into electrospun dressing for efficient bacteria-infected wound healing as confirmed by both in vitro and in vivo tests. [Display omitted] Silver nanoparticles (AgNPs) have been widely recognised as effective antibacterial materials in textiles for enhancing wound healing. However, high loadings of AgNPs are toxic and expensive. Thus, it is ideal to prepare AgNPs in a favourable nanostructure for stable and effective conjugation with the textile carrier by selecting a reductant and stabiliser that contributes to the antibacterial effect. Here, silver nanoparticles/vanadium oxide nanowires (Ag/VO x NWs) were prepared via a one-step reduction strategy using vanadium oxide quantum dots (VO x QDs) as both the reductant and stabiliser. VO x QDs possess antibacterial properties, which aid in minimising the applied silver content while enhancing bactericidal performance. Silver can self-aggregate into nanoparticles as well as promote the formation of vanadium oxide nanowires (VO x NWs). Accordingly, the Ag/VO x NWs exhibited remarkable antibacterial effects against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The nanowire structure of the Ag/VO x NWs was favourable for effective loading into a sodium alginate (SA) gel fabric to form a wound dressing. The effective loading of Ag/VO x NWs on SA was conducive to the complete dispersion of the bacteriostatic agent and enhanced the antibacterial activity of AgNPs. The wound dressing efficiently suppressed the growth of wound bacteria and promoted wound healing in vivo. [ABSTRACT FROM AUTHOR]

Staphylococcus haemolyticus is a cause of bovine mastitis, leading to inflammation in the mammary gland. This bacterial infection adversely affects animal health, reducing milk quality and yield. Its emergence has been widely reported, representing a significant economic loss for dairy farms. Interestingly, S. haemolyticus exhibits higher levels of antimicrobial resistance than other coagulase-negative Staphylococci. In this study, we synthesized silver/silver chloride nanoparticles (Ag/AgCl-NPs) using Solanum lasiocarpum root extract and evaluated their antibacterial and antibiofilm activities against S. haemolyticus. The formation of the Ag/AgCl-NPs was confirmed using UV–visible spectroscopy, which revealed maximum absorption at 419 nm. X-ray diffraction (XRD) analysis demonstrated the crystalline nature of the Ag/AgCl-NPs, exhibiting a face-centered cubic lattice. Fourier transform infrared (FT-IR) spectroscopy elucidated the functional groups potentially involved in the Ag/AgCl-NPs synthesis. Transmission electron microscopy (TEM) analysis revealed that the average particle size of the Ag/AgCl-NPs was 10 nm. Antimicrobial activity results indicated that the minimum inhibitory concentration (MIC) and maximum bactericidal concentration (MBC) of the Ag/AgCl-NPs treatment were 7.82–15.63 μg/mL towards S. haemolyticus. Morphological changes in bacterial cells treated with the Ag/AgCl-NPs were observed under scanning electron microscopy (SEM). The Ag/AgCl-NPs reduced both the biomass of biofilm formation and preformed biofilm by approximately 20.24–94.66 % and 13.67–88.48 %. Bacterial viability within biofilm formation and preformed biofilm was reduced by approximately 21.56–77.54 % and 18.9–71.48 %, respectively. This study provides evidence of the potential of the synthesized Ag/AgCl-NPs as an antibacterial and antibiofilm agent against S. haemolyticus. • Ag/AgCl-NPs were synthesized using S. lasiocarpum root extract. • Ag/AgCl-NPs showed potent antibacterial and antibiofilm activity. • Ag/AgCl-NPs reduced biofilm biomass and bacterial cell viability. [ABSTRACT FROM AUTHOR]

Medicinal plants have been widely used for their antimicrobial properties against various microorganisms. Arisaema dracontium a familiar medicinal plant, was analyzed and silver nanoparticles (AgNPs) were synthesized using extracts of different parts of its shoot including leaves and stem. Further, the antimicrobial activity of different solvent extracts such as ethyl acetate, n-hexane, ethanol, methanol, and chloroform extracts were analyzed. AgNPs were prepared using aqueous silver nitrate solution and assessed their antibacterial activity against multidrug-resistant (MDR) and Non-multidrug-resistant bacteria. The characterization of AgNPs was done by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), UV–visible spectroscopy, Fourier Transform Infrared (FTI), and X-ray Diffraction approaches. The leaf extract contained Tannins, Flavonoids, Terpenoids, and Steroids while Alkaloids, Saponins, and Glycosides were undetected. The stem extract contained Alkaloids, Tannins, Flavonoids, Saponins, Steroids, and Glycosides while Terpenoids were not observed. The AgNPs synthesized from stem and leaf extracts in the current study had spherical shapes and ranged in size from 1 to 50 nm and 20–500 nm respectively as were visible in TEM. The leaf extract-prepared AgNPs showed significantly higher activities i.e., 27.75 mm ± 0.86 against the MDR strains as compared to the stem-derived nanoparticles i.e., 24.33 ± 0.33 by comparing the zones of inhibitions which can be attributed to the differences in their phytochemical constituents. The acute toxicity assay confirmed that no mortality was noticed when the dosage was 100 mg per kg which confirms that the confirms that the AgNPs are not toxic when used in low quantities. It is concluded that leaf extract from A. dracontium could be used against pathogenic bacteria offering economic and health benefits compared to the chemical substances. [Display omitted] • To explore the phytoconstituents of the Arisaema dracontium which are involved in the capping and stabilizing agent in nanoparticles synthesis. • Green synthesis as an Eco-friendly technique to synthesize AgNPs without consumption of huge amount of energy and chemicals. • Characterization of the AgNPs via SEM, TEM, EDX, XRD, FTIR, and UV. • The study has engrossed on the outcome of AgNPs antimicrobial activities. • The current study also focused to investigate its toxicological properties of the prepared nanoparticles. [ABSTRACT FROM AUTHOR]

The global rise of antibiotic resistance poses a substantial risk to mankind, underscoring the necessity for alternative antimicrobial options. Developing novel drugs has become challenging in matching the pace at which microbial resistance is evolving. Recently, nanotechnology, coupled with natural compounds, has emerged as a promising solution to combat multidrug-resistant bacteria. In the present study, silver nanoparticles were green-synthesized using aqueous extract of Phoenix dactylifera (variety Ajwa) fruits and characterized by UV–vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) coupled with Energy dispersive X-ray analysis (EDX), Transmission electron microscopy (TEM) and Thermogravimetric-differential thermal analysis (TGA-DTA). The in-vitro synergy of green synthesized P. dactylifera silver nanoparticle (PD-AgNPs) with selected antibiotics and bioactive extract of Punica granatum, i.e., ethyl acetate fraction (PGEF), was investigated using checkerboard assays. The most effective synergistic combination was evaluated against the QS-regulated virulence factors production and biofilm of Pseudomonas aeruginosa PAO1 by spectroscopic assays and electron microscopy. In-vivo anti-infective efficacy was examined in Caenorhabditis elegans N2 worms. PD-AgNPs were characterized as spherical in shape with an average diameter of 28.9 nm. FTIR analysis revealed the presence of functional groups responsible for the decrease and stabilization of PD-AgNPs. The signals produced by TGA-DTA analysis indicated the generation of thermally stable and pure crystallite AgNPs. Key phytocompounds detected in bioactive fractions include gulonic acid, dihydrocaffeic acid 3-O-glucuronide, and various fatty acids. The MIC of PD-AgNPs and PGEF ranged from 32 to 128 μg/mL and 250–500 μg/mL, respectively, against test bacterial strains. In-vitro , PD-AgNPs showed additive interaction with selected antibiotics (FICI 0.625–0.75) and synergy with PGEF (FICI 0.25–0.375). This combination inhibited virulence factors by up to 75 % and biofilm formation by 84.87 % in P. aeruginosa PAO1. Infected C. elegans worms with P. aeruginosa PAO1 had a 92.55 % survival rate when treated with PD-AgNPs and PGEF. The combination also reduced the reactive oxygen species (ROS) level in C. elegans N2 compared to the untreated control. Overall, these findings highlight that biosynthesized PD-AgNPs and bioactive P. granatum extract may be used as a potential therapeutic formulation against MDR bacteria. • Silver nanoparticles from aqueous extract of P. dactylifera (PD-AgNPs) were well-dispersed and spherical, with an average diameter of 28.9 nm. • PD-AgNPs and bioactive extract of P. granatum (PGEF) showed synergy in vitro with FICI of 0.25–0.375. • Synergistic formulation inhibited QS-regulated virulence factors in P. aeruginosa PAO1 more than 75 %.. • The anti-infective efficacy of synergistic formulations against P. aeruginosa PAO1-infected C. elegans N2 worms highlights in vivo therapeutic potential.. [ABSTRACT FROM AUTHOR]

The plant Erythrina indica comes under Fabaceae family, mainly used for used in traditional medicine as nervine sedative, antiepileptic, antiasthmatic, collyrium in opthalmia, antiseptic. Current study focused synthesize of silver nanoparticles (AgNPs) by E. indica leaf ethanol extract. The green-synthesized AgNPs underwent characterization using multiple analytical techniques, including UV–visible, FTIR, DLS, SEM, TEM, XRD, and EDX, and estimation of their antioxidant activity and antimicrobial activity. Phytochemical analysis identified alkaloids, tannins, saponins, flavonoids, and phenols as secondary metabolites. The Total Phenol Content (TPC) was determined to be 237.35 ± 2.02 mg GAE-1, indicating a substantial presence of phenolic compounds. The presence of AgNPs was verified through UV–Visible analysis at 420 nm, and FT-IR revealed characteristic phenolic functional groups. DLS analysis indicated a narrow size distribution (polydispersity index - PDI: 3.47%), with SEM revealing spherical AgNPs of approximately 20 nm. TEM showed homogeneous, highly polycrystalline AgNPs with lattice spacing at 0.297. XRD analysis demonstrated crystallinity and purity, with distinct reflection peaks corresponding to miller indices of JCPDS card no. 01 087 1473. In vitro , AgNPs exhibited robust antioxidant activity like; DPPH, ABTS, and H 2 O 2 , surpassing E. indica -assisted synthesis. ABTS assay indicated higher antioxidant activity (81.94 ± 0.05%) for AgNPs at 734 nm, while E. indica extraction showed 39.67 ± 0.07%. At 532 nm, both E. indica extraction (57.71 ± 0.11%) and AgNPs (37.41 ± 0.17%) exhibited H 2 O 2 scavenging. Furthermore, AgNPs displayed significant antimicrobial properties, inhibiting Staphylococcus aureus (15.7 ± 0.12 mm) and Candida albicans (10.7 ± 0.17 mm) byfor the concentration of 80 μg/mL. Through the characterizations underscore of the potential of Erythrina indica -synthesized AgNPs, rich in polyphenolic compounds, for pharmacological, medical, biological applications and antipyretic properties. [Display omitted] • Green Synthesized of Silver Nanoparticles (AgNPs) using Erythrina indica ethanol extract as reducing and capping agent. • The significant concentration of total phenol content (237.35 ± 2.02 mg GAE-1). • SEM revealing spherical AgNPs of approximately 20 nm. • TEM showed homogeneous, highly polycrystalline AgNPs with lattice spacing at 0.297. • The in-vitro antioxidant and antimicrobial properties, along with pharmacological and biological applications, as well as antipyretic properties. [ABSTRACT FROM AUTHOR]

This research paper presents a novel approach to the green synthesis of silver nanoparticles (AgNPs) using viticultural waste, allowing to obtain NP dispersions with distinct properties and morphologies (monodisperse and polydisperse AgNPs, referred to as mAgNPs and pAgNPs) and to compare their biological activities. Our synthesis method utilized the ethanolic extract of Vitis vinifera pruning residues, resulting in the production of mAgNPs and pAgNPs with average sizes of 12 ± 5 nm and 19 ± 14 nm, respectively. Both these AgNPs preparations demonstrated an exceptional stability in terms of size distribution, which was maintained for one year. Antimicrobial testing revealed that both types of AgNPs inhibited either the growth of planktonic cells or the metabolic activity of biofilm sessile cells in Gram-negative bacteria and yeasts. No comparable activity was found towards Gram-positives. Overall, pAgNPs exhibited a higher antimicrobial efficacy compared to their monodisperse counterparts, suggesting that their size and shape may provide a broader spectrum of interactions with target cells. Both AgNP preparations showed no cytotoxicity towards a human keratinocyte cell line. Furthermore, in vivo tests using a silkworm animal model indicated the biocompatibility of the phytosynthesized AgNPs, as they had no adverse effects on insect larvae viability. These findings emphasize the potential of targeted AgNPs synthesized from viticultural waste as environmentally friendly antimicrobial agents with minimal impact on higher organisms. • Vitis vinifera pruning residues: an excellent source for green AgNPs synthesis. • AgNPs of different morphology are active against a broad spectrum of pathogens. • V. vinifera -derived AgNPs display anti-biofilm activity. • Polydisperse AgNPs exhibit a higher antimicrobial efficacy. • Effective concentrations of AgNPs show low cytotoxicity and in vivo toxicity. [ABSTRACT FROM AUTHOR]

The high-level of glucose in daily nutrition causes diabetes (Diabetes mellitus) and obesity. It is also important to determine glucose levels in food production processes for quality control methods. Biosensors are bio analytical devices that provides cheap, simple, analyses and have a fast response time. Silver nanoparticles are used to modify electrodes in bio-sensing glucose. The nanoparticles could be synthesized via the green synthesis technique. In this technique, plants could be used both reducing and stabilizing agents. Agricultural waste, an environmental problem, is increasing with the population. These wastes are a good natural source and have the potential for green synthesis of silver nanoparticles to use in biosensor applications. In this study, a new amperometric glucose biosensor was designed. For this purpose, carbon paste electrode (CPE) was modified by green synthesized waste tea based silver nanoparticles (WT-AgNPs) and the glucose oxidase enzyme was immobilized on MCPE by the cross-linking. Glucose determination was performed based on the reduction of hydrogen peroxide at +0.4 V versus Ag/AgCl. The linear working range was determined as 0.10–1.0 µM. In addition, the designed biosensor was applied to detect the amount of glucose in a commercial fruit juice. The results showed that the designed biosensor has low detection limit, very good reproducibility, selectivity, and almost long shelf life. • Food glucose levels must be determined cheaply and rapidly. • Biosensors provides cheap, simple, analyses and have a fast response time. • Agricultural wastes with their bio compounds could be used in silver nanoparticle synthesize. • In this study, waste black tea leaves based silver nanoparticles were synthesized. • The nanoparticles were used to prepare a new amperometric glucose biosensor. [ABSTRACT FROM AUTHOR]

In this study, tungsten disulfide quantum dots (WS 2 QDs) and silver nanoparticles (AgNPs) were applied to establish a dual-mode fluorometric and smartphone-based colorimetric sensor for the determination of cyanide ions (CN⁻). We indicated that the fluorescence intensity of WS 2 QDs was quenched by AgNPs as a result of the inner filter effect (IFE) mechanism. Moreover, the quenched fluorescence intensity of WS 2 QDs switched on again in the presence of CN⁻ due to the interaction between AgNPs and CN⁻, leading to destroy AgNPs, diminishing their yellow color and reducing their IFE on WS 2 QDs. Based on these facts, we established a turn-off-on fluorometric (with a range of 0.5–30 and detection limits of 0.17 µM) and smartphone-based colorimetric sensor (with 5–500 µM and detection limits of 1.2 µM) for CN⁻ measurement. The sensor was exploited for CN⁻ analysis in water and food samples with satisfactory results. The established dual sensor benefits from both methods advantages such as the high sensitivity of fluorometric sensors as well as simple and visual detection of smartphone-based colorimetric sensors. Additionally, our developed smartphone-based colorimetric sensor can be used as a portable sensor for the sensitive, rapid and low-cost analysis of CN⁻ in the field. [Display omitted] • WS 2 QDs and AgNPs were exploited to design a dual fluorometric and smartphone based colorimetric sensor for detection of CN⁻. • WS 2 QDs acted as a fluorophore and AgNPs acted as a quencher and colorimetric agent. • The quenching mechanism of WS 2 QDs/ AgNPs were studied and attributed to the IFE. • The fluorometric and colorimetric sensing mechanism was attributed to the destruction of AgNPs by CN-. • The dual fluorometric and smartphone based colorimetric sensor was applied to detect CN⁻ in food and water samples. [ABSTRACT FROM AUTHOR]

The good antimicrobial properties of silver make it widely used in food, medicine, and environmental applications. However, the release and accumulation of silver-based antimicrobial agents in the environment is increasing with the extensive use of silver-based antimicrobials, and the prevalence of silver-resistant bacteria is increasing. To prevent the emergence of superbugs, it is necessary to exercise rational and strict control over drug use. The mechanism of bacterial resistance to silver has not been fully elucidated, and this article provides a review of the progress of research on the mechanism of bacterial resistance to silver. The results indicate that bacterial resistance to silver can occur through inducing silver particles aggregation and Ag+ reduction, inhibiting silver contact with and entry into cells, efflux of silver particles and Ag+ in cells, and activation of damage repair mechanisms. We propose that the bacterial mechanism of silver resistance involves a combination of interrelated systems. Finally, we discuss how this information can be used to develop the next generation of silver-based antimicrobials and antimicrobial therapies. And some antimicrobial strategies are proposed such as the "Trojan Horse" - camouflage, using efflux pump inhibitors to reduce silver efflux, working with "minesweeper", immobilization of silver particles. [ABSTRACT FROM AUTHOR]

In this work, harvested mushroom substrate (HMS) has been explored for the first time through a comprehensive optimization study for the green synthesis of silver nanoparticles (AgNPs). A multiple response central composite design with three parameters: pH of the reaction mixture, temperature, and incubation period at three distinct levels was employed in the optimization study. The particle size of AgNPs, UV absorbance, and the percentage of Ag/Cl elemental ratio were considered as the response parameters. For each response variable examined the model used was found to be significant (P < 0.05). The ideal conditions were: pH 8.9, a temperature of 59.4 °C, and an incubation period of 48.5 h. The UV–visible spectra of AgNPs indicated that the absorption maxima for AgNP–3 were 414 nm, 420 for AgNPs–2, and 457 for AgNPs-1. The XRD analysis of AgNPs-3 and AgNPs-2 show a large diffraction peak at ∼38.2°, ∼44.2°, ∼64.4°, and ∼77.4°, respectively, which relate to the planes of polycrystalline face-centered cubic (fcc) silver. Additionally, the XRD result of AgNPs–1, reveals diffraction characteristics of AgCl planes (111, 200, 220, 311, 222, and 400). The TEM investigations indicated that the smallest particles were synthesized at pH 9 with average diameters of 35 ± 6 nm (AgNPs–3). The zeta potentials of the AgNPs are −36 (AgNPs–3), −28 (AgNPs–2), and −19 (AgNPs–1) mV, respectively. The distinct IR peak at 3400, 1634, and 1383 cm−1 indicated the typical vibration of phenols, proteins, and alkaloids, respectively. The AgNPs were further evaluated against gram (+) strain Bacillus subtilis (MTCC 736) and gram (−) strain Escherichia coli (MTCC 68). All of the NPs tested positive for antibacterial activity against both bacterial strains. The study makes a sustainable alternative to disposing of HMS to achieve the Sustainable Development Goals (SDGs). [Display omitted] • Harvested Mushroom Substrate utilized for the synthesis of silver nanoparticles. • The synthesis process was further optimized with central composite design. • PH > 9 yielded better morphology of synthesized silver nanoparticles. • The average size of the silver nanoparticles at pH > 9 was 35 ± 6 nm. • Highest bactericidal activity of silver nanoparticles were observed in 6.96 ± 0.03 ppm. [ABSTRACT FROM AUTHOR]

[Display omitted] Globally, drug-resistant bacteria are a potential threat to human society owing to the overuse of antibiotics and thus, non-antibiotic bactericides are urgently needed. Herein, an innovative antibacterial nanoplatform based on quaternized chitosan (QCS)/ silver (Ag)/ cobalt phosphide (CoP) nanocomposites is envisaged for achieving near-infrared (NIR) laser-inducible rapid sterilisation. In the core-shell hybrids, Ag nanoparticles (NPs) with a size of ∼ 25 nm were uniformly deposited on CoP nanoneedles, upon which a layer of QCS (approximately 10 wt%), is coated. Numerical calculations revealed that under NIR irradiation, high-energy hot electrons arising from the surface plasmon resonance effect of Ag migrate into the interface between Ag and CoP, and amplify the photothermal effect of CoP. Meanwhile, photo-excited electrons from CoP are transported onto Ag NPs because the Schottky heterostructure facilitates the production of reactive oxygen species. Ag loading simultaneously enhances the photocatalytic and photothermal effects of CoP, achieving rapid antibacterial activity synergistically. The QCS coating improves the dispersibility of power in an aqueous system and provides contact between the antiseptics and bacteria. The ternary QCS/Ag/CoP nanocomposites achieved greater than 99.6% inactivation against S. aureus and E. coli within 10 min. In addition, the nanocomposites were confirmed to be noncytotoxic to mammals. Consequently, the QCS/Ag/CoP nanoplatforms possess great potential for rapid and effective antibacterial applications. [ABSTRACT FROM AUTHOR]

In recent years, because of the various functions associated with silver nanoparticles (AgNPs) in manufacturing, different ways for their synthesis have been established. The antioxidant and antibacterial effects of terebinth (Pistacia terebinthus) have been proven. In this study, for the first time, using the extract of terebinth, we have synthesized AgNPs using a green method. Ultraviolet–visible spectrophotometry, X-ray diffraction (XRD), Infrared spectroscopy (FTIR), and the field emission scanning electron microscopy (FE-SEM) spectroscopy analyses were applied to evaluate and verify the formation of NPs, and the antioxidant, antibacterial and anticancer activity of synthesized AgNPs was also studied. The highest absorption was obtained 24 h following the synthesis at 420 nm because of the Ag + to Ag0 reduction. The functional groups stabilizing activity was obtained by FTIR. Moreover, size and surface morphology were assessed by FE-SEM. The present research showed the AgNPs had spherical shape and had a 32 nm diameter. The face-centered cubic construction of AgNPs was evaluated through XRD method with peaks at 2θ = 37°, 49°, 63°, and 76° (related to the planes of silver 111, 200, 220, 311), respectively. Antimicrobial assessment revealed that the biosynthesized AgNPs had a great antimicrobial activity in response to Gram-positive and Gram-negative strains. Suppression of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was determined to be associated with dosage. In addition, a high anticancer activity, against MCF-7 cell line, was observed for the 25 μg/mL concentration of the AgNPs. Altogether, these results show that biogenic AgNPs can be functioned as beneficial medicinal compounds. • Using the extract of terebinth, AgNPs were synthesized using a green method. • AgNPs had an antimicrobial activity against Gram-positive and Gram-negative strains. • AgNPs had a high antioxidant and anticancer activity, against MCF-7 cell line. [ABSTRACT FROM AUTHOR]

[Display omitted] The introduction of various drugs onto commercial soft contact lenses (CLs) has emerged as a potentially effective strategy for treating microbial keratitis (MK) because drug-loaded CLs can maintain a controlled drug concentration which leaded to enhanced drug bioavailability and reduced side effects in ocular tissues. In this study, silver nanoparticles modified with zwitterionic poly (carboxybetaine- co -dopamine methacrylamide) copolymer (PCBDA@AgNPs) as novel anti-infective therapeutics were prepared and firmly immobilized onto soft CLs through mussel-inspired surface chemistry. The obtained PCBDA@AgNPs coated CL (PCBDA@AgNPs-CL) remained the excellent transparency of commercial CLs and exhibited strong and broad-spectrum antimicrobial activities. We systematically explored the mechanism and found that the functional CLs can effectively inhibit the growth of microbial biofilms via a synergic "resist–kill–remove" strategy due to the zwitterionic surface and sustained release of silver ions. Significantly, in vitro cell cytotoxicity and in vivo subcutaneous implantation experiments proved the significant biosafety of PCBDA@AgNPs-CL. Furthermore, PCBDA@AgNPs-CL was successfully employed for the in vivo treatment of MK rabbit models, demonstrating excellent abilities to eradicate microbe-induced ocular infections and to prevent the destruction and irreversible structural alterations of corneal tissues. Collectively, PCBDA@AgNPs-CL is therefore a highly promising therapeutic device to significantly boost the efficacy for MK treatment. [ABSTRACT FROM AUTHOR]

A complex nanostructure composed of silver nanocrystals randomly immobilized carbon nanoparticles randomly immobilized carbon nanoparticles was in situ synthesized by one-step solvothermal method using Toluene as carbon sources. [Display omitted] Silver nanoparticles (Ag NPs) have attracted extensive research interest in bioimaging and biosensing due to their unique surface plasmon resonance. However, the potential aggregation and security anxiety of Ag NPs hinder their further application in biomedical field due to their high surface energy and the possible ionization. Here, binary heterogeneous nanocomplexes constructed from silver nanoparticles and carbon nanomaterials (termed as C-Ag NPs) were reported. The C-Ag NPs with multiple yolk structure were synthesized via a one-step solvothermal route using toluene as carbon precursor and dispersant. The hydrophilic functional groups on the carbon layer endowed the C-Ag NPs excellent chemical stability and water-dispersity. Results showed that C-Ag NPs demonstrated excellent safety profile and excellent biocompatibility, which could be used as an intracellular imaging agent. Moreover, the C-Ag NPs responded specifically to hydroxyl radicals and were expected to serve as a flexible sensor to efficiently detect diseases related to the expression of hydroxyl radicals in the future. [ABSTRACT FROM AUTHOR]

[Display omitted] Burn wounds are susceptible to bacterial infections and are usually accompanied by a large amount of exudate, making the treatment of burn wounds a challenge in the clinic. Here, we developed a biodegradable cryogel with high water absorption and good antibacterial and antibiofilm activity based on gelatin (GT) and silver nanoparticles (Ag NPs) to promote burn wound healing. The porous GT/Ag cryogel had a swelling ratio of up to 4000%, effectively absorbing wound exudate and allowing for gas exchange. Moreover, the GT/Ag cryogel had an excellent killing effect on methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (PA), which burn wounds are susceptible to, and can effectively remove mature biofilms. In the rat liver defect noncompressible hemorrhage model, GT/Ag cryogels with shape memory performance showed better hemostatic ability than commercial gelatin sponges. Most importantly, the GT/Ag cryogel was more effective than the TegadermTM dressing and GT cryogel in promoting wound contraction, collagen deposition, and angiogenesis and reducing inflammation in a PA-infected burn wound model. In addition, GT/Ag cryogels degraded in the body within 4 weeks, which alleviated the pain of peeling the dressing from the wound. Therefore, GT/Ag cryogels with outstanding antibacterial properties and effective absorption of wound exudates are excellent candidates for wound dressings to promote burn wound repair. [ABSTRACT FROM AUTHOR]

Ordered arrays of Ag nanoparticles-assembled cavities are fabricated by templated electrodeposition and post-growth. Oriented attachment and Ostwald ripening are proposed to drive the post-growth process. Such Ag cavity array shows high surface-enhanced Raman scattering sensitivity to pesticides (thiram and paraquat). [Display omitted] • Three-dimensional Ag nanostructure arrays have been fabricated by a simple method. • Ag nanoparticles-assembled micro-cavity arrays were achieved using templated electrodeposition and post-growth. • The three-dimensional substrate with dense hotspots showed high SERS sensitivity. • The fabricated SERS substrate showed high spectral uniformity and reproducibility. • Sensitive SERS detection of pesticide residues on fruits was realized. Three-dimensional (3D) plasmonic nano-arrays can provide high surface-enhanced Raman scattering (SERS) sensitivity, good spectral uniformity and excellent reproducibility. However, it is still a challenge to develop a simple and efficient method for fabrication of 3D plasmonic nano-arrays with high SERS performance. Here we report a facile approach to construct ordered arrays of silver (Ag) nanoparticles-assembled spherical micro-cavities using polystyrene (PS) sphere template-assisted electrodeposition and post-growth. The electrodeposited small Ag nanoparticles grow into bigger stable nanoparticles during the post-growth process, which could significantly improve the SERS sensitivity. The Ag nanoparticles-assembled 3D micro-cavity array provides much more hotspots in the excitation laser beam-covered volume than the two-dimensional counterpart. The relative standard deviation (RSD) of 612 cm−1 peak of rhodamine 6G (R6G) was calculated to be 8%, and the RSD of the characteristic peak taken from substrates of different batches was less than 10%. The detectable lower concentration as low as 1 fM was achieved for an aqueous solution of R6G. Such SERS substrate also showed high sensitivity to thiram (fungicide) and paraquat (herbicide) in water with limits of detection of 0.067 nM and 2.5 nM respectively. Furthermore, it also demonstrated that SERS detection of pesticide residues on fruits can be realized, showing a potential application in rapid monitoring food safety. [ABSTRACT FROM AUTHOR]

[Display omitted] Metallic nanoparticles of various shapes and sizes can be synthesised through a diversity of bottom-up pathways, such as precipitation induced by chemical reduction. Varying composition, by adjusting concentrations or adding/replacing species, is the predominant strategy to tune nanoparticles structures. However, controlling time down to the onset of precipitation, nucleation, should also provide a powerful means to control nanostructuration. We perform sequential reagent additions with a time resolution down to the millisecond. We use a millifluidic continuous flow setup consisting of tangential mixers in series, which allows flow rates up to dozens of litres per hour. We systematically vary both addition order and delay for each reagent involved in the synthesis of silver nanoplates. The resulting dispersions are compared using UV–visible spectroscopy, transmission electron microscopy and small-angle X-ray scattering. We show that synthesis pathways differing only in the order of sub-second additions lead to drastically different synthetic outcomes. Silver nanoparticles of different shapes and sizes, displaying an array of plasmonic colours, are synthesised at the same final composition by tuning the composition pathways along time. Our results unlock a previously inaccessible portion of the space of parameters, which will lead to an enhanced structural diversity, control and understanding of nanoparticles syntheses. [ABSTRACT FROM AUTHOR]

[Display omitted] A facile one-step method was developed to synthesize magnetically separable nanocomposite with a h-Fe 3 O 4 core and an Ag/polydopamine hybrid shell, of which exhibited excellent catalytic activity, antibacterial activity, and recyclability. A facile one-step method for synthesis of magnetic core–shell nanocomposite composed of h-Fe 3 O 4 (hollow Fe 3 O 4) core and stable PDA (polydopamine) shell with functional Ag NPs (silver nanoparticles) evenly distributed between them is developed. The h-Fe 3 O 4 @Ag/PDA nanocomposite showed excellent catalytic activity in the reaction for reducing azo dyes (methyl orange, methylene blue, and congo red), and the ratios of k values to the weight of h-Fe 3 O 4 @Ag/PDA were calculated to be 0.302, 0.0545, and 0.895 min−1 mg−1, respectively. Besides, the h-Fe 3 O 4 @Ag/PDA nanocomposite also exhibited good antibacterial activity in the experiment of culturing Bacillus subtilis , and the MIC (minimum inhibitory concentration) was as low as 12.5 μg/mL. Because the Ag NPs will not be leached in the solution under the protection of the PDA shell, the catalytic and antibacterial activities of h-Fe 3 O 4 @Ag/PDA nanocomposite could maintain more than 90% after five cycles. Intriguingly, this simple synthetic method can be extended to fabricate different multifunctional nanocomposites such as the spherical SiO 2 @Ag/PDA and rod-like Fe 2 O 3 @Ag/PDA. Overall, the facile fabrication process, the superior catalytic and antibacterial activity, and the excellent stability, endow the h-Fe 3 O 4 @Ag/PDA to be a promising nanocomposite. [ABSTRACT FROM AUTHOR]

The colonization of pathogenic microbes poses a significant clinical barrier that hinders the physiological wound-healing process. Addressing this challenge, we developed a novel wound dressing using a modified cotton gauze dressing coated with fucoidan and functionalized with silver nanoparticles (LB-Ag NPs–FN–OCG) for the rapid treatment of infected wounds. Firstly, phytochemical-capped LB-Ag NPs were synthesized and characterized using high performance liquid chromatography (HPLC), transmission electron microscopy (TEM), and zeta potential analysis. Secondly, different concentrations of LB-Ag NPs (0.1%–1%) were functionalized into FN-OCG to identify appropriate concentrations that were non-toxic with superior antibacterial activities. Screening assays, including antibacterial, hemolysis, chick chorioallantoic membrane (CAM) assay, and cytotoxicity assay, revealed that LB-Ag NPs (0.5%)–FN–OCG were non-toxic and demonstrated greater efficiency in inhibiting bacterial pathogens (Escherichia coli, Salmonella enterica, Staphylococcus aureus, and Listeria monocytogenes) and promoting fibroblast cell (NIH3T3) migration. In vivo assays revealed that LB-Ag NPs (0.5%)–FN–OCG treatment exhibited excellent wound healing activity (99.73 ± 0.01%) compared to other treatments by inhibiting bacterial colonization, maintaining the blood parameters, developing granulation tissue, new blood vessels, and collagen deposition. Overall, this study highlights that LB-Ag NPs (0.5%)–FN–OCG serve as a antibacterial wound dressing for infected wound healing applications. [Display omitted] • Biogenic Ag NPs and fucoidan-loaded cotton dressings (LB-Ag NPs–FN–OCG) were developed. • The antibacterial and wound healing efficiency of LB-Ag NPs–FN–OCG was evaluated. • LB-Ag NPs–FN–OCG had significant antibacterial activity. • LB-Ag NPs–FN–OCG were nontoxic and promising in infectious wound healing therapy. [ABSTRACT FROM AUTHOR]

The morphology optimization and non-metallic doping of Ag catalyst were realized by a facile and efficient plasma vulcanization treatment. The prepared sulfide derived Ag porous microrods (SD-AgPMRs) demonstrates high Faradaic efficiency and partial current density for CO production at low potentials in the electrocatalytic CO 2 RR. [Display omitted] • The SD-AgPMRs were firstly fabricated by a H 2 S plasma-enhanced low-temperature solid-state activation process. • This work realized the dual channel optimization of Ag electrode in morphology and composition. • Effective CO 2 reduction were realized which contribute to larger specific surface area and the introduction of S atoms. Metal electrode is considered as an ideal candidate for electrocatalytic carbon dioxide (CO 2) reduction considering its excellent chemical stability, application potential and eco-friendly properties. Optimization process such as morphological control, non-metallic doping, alloying is widely studied to improve the efficiency of metal electrodes. In this work, we successfully improved the CO 2 reduction performance of silver using a facile plasma vulcanization treatment. The obtained sulfide derived silver (Ag) porous microrods (SD-AgPMRs) are optimized from both morphology and composition aspects, and demonstrates high Faradaic efficiency and partial current density for carbon monoxide (CO) production at low potentials. The larger specific surface area of porous microrod structure and the improved adsorption energy of important intermediates in comparison with Ag foil are realized by introduction of sulfur (S) atoms after plasma vulcanization activation, as suggested by density functional theory (DFT) calculations. This work presents a novel strategy to optimize metal electrocatalysts for CO 2 reduction as well as to improve catalysis in other fields. [ABSTRACT FROM AUTHOR]

[Display omitted] • Porous Ag dendrites foam (ADDF) over Ag rods are first synthesized. • The effects of capping agent type and deposition current on catalyst morphology are investigated. • ADDF-2 catalyst exhibited a remarkable j CO of −288.68 mA cm−2 at 9.5 bar. Ultrathin Ag nanosheets (ANS), rice spike-like Ag dendrites (ADD) and porous Ag dendrites foam (ADDF) are synthesized respectively via a capping agent and electric field-induced Ag crystals growth approach. Compared with ANS and ADD, ADDF catalysts possess significantly increased CO Faradaic efficiency (FE) and can be operated at a broader applied current range due to the inter-connective porous macrostructure of ADDF catalysts with more abundant active sites, which can afford plenty of pore channels to substantially impel CO 2 diffusion to reaction sites, therefore maintaining a high rate of CO 2 reduction. Furthermore, unique conical microstructure can intensify the local electric field to raise the CO 2 concentration at the reaction sites. ADDF-2 exhibits a CO Faradaic efficiency of 96.84% at −28.8 mA cm−2 in a membrane microchannel reactor at an optimal gas–liquid ratio of 1:2. To increase the CO 2 concentration, by increasing the CO 2 pressure (3∼9.5 bar), so that CO partial current density can reach −288.68 mA cm−2, which is the highest one achieved so far in the liquid phase with neutral pH. [ABSTRACT FROM AUTHOR]

Tannic acid is used as a green and efficient stabilizer to fabricate all kinds of TMNPs including AuNPs, AgNPs, CuNPs and PdNPs. These TMNPs possess small sizes ranging from 1 nm to 6 nm, which is conducive to several catalytic reactions in aqueous solution, such as 4-nitrophenol (4-NP) reduction, CuAAC reactions and Suzuki–Miyaura coupling reactions. This present work has the superiorities of green raw material, simple and efficient preparation process, high catalytic activities, as well as the applicability and generality for various substrates. [Display omitted] Due to the good electrical, optical, magnetic, catalytic properties, transition metal nanoparticles (TMNPs) have been becoming more and more interesting in the fileds of environment, material, biomedicine, catalysis, and so on. Here, tannic acid (TA) is used as a green and efficient stabilizer to fabricate all kinds of TMNPs including AuNPs, AgNPs, CuNPs and PdNPs. These TMNPs possess small sizes ranging from 1 nm to 6 nm, which is conducive to several catalytic reactions in aqueous solution, such as 4-nitrophenol (4-NP) reduction, CuAAC reactions and Suzuki–Miyaura coupling reactions. AuNPs and PdNPs are found to have distinctly higher catalytic activities than AgNPs and CuNPs in the 4-NP reduction process. Especially, PdNPs show the highest catalytic activities with TOF up to 7200 h−1 in the 4-NP reduction. Furthermore, PdNPs also exhibit satisfying catalytic performance in the Suzuki–Miyaura coupling process, and CuNPs are catalytically active in the copper-catalyzed azide alkyne cycloaddition (CuAAC) reactions. The applicability and generality of PdNPs and CuNPs are respectively confirmed via the reaction between different substrates in the Suzuki–Miyaura coupling reactions and the CuAAC reactions. This work present a simple, fast, green and efficient strategy to synthesize TMNPs for multiple catalysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Silver nanoparticles (Ag NPs) stabilized by four different capping agents are applied as catalysts of CO 2 reduction in a zero-gap gas-flow electrolyser. • Branched polyethylenimine (BPEI), polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), and citrate are used as capping agents. • Depending on the nature of the capping agent, Ag NPs undergo different degradation pathways. • BPEI is the most effective stabilizer but also blocks CO 2 reduction the most. • Particles capped by PVP tend mostly to corrode (leading to particle shrinkage) while in case of PEG- and citrate-capped particles degradation involves particle size growth. • The statistical analysis of SEM images and WAXS measurements provide an insight to the degradation pathway. • Ligand exchange and removal experiments underline the role of capping agents in catalyst degradation. We apply silver nanoparticles (Ag NPs) as catalysts of CO 2 reduction in a zero-gap gas-flow electrolyser. Ag NPs stabilized by different ligands —branched polyethylenimine (BPEI), polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), and citrate— are used in the experiments. The as-prepared NPs have almost identical initial size distributions, yet their catalytic performance, in terms of achievable current and CO selectivity, is different. During electrolysis all Ag NPs exhibit unambiguous morphology changes; the degradation pathway they follow, however, markedly depends on the chemical nature of the capping agent stabilizing them. Scanning electron micrographs obtained before and after constant-charge electrolyses carried out at different potentials reveal that amongst the studied ligands, BPEI seems to be the most effective stabilizer of Ag NPs; in turn, however, BPEI also limits CO formation the most. In case of PVP, mostly corrosion (particle shrinkage) is observed at practically relevant electrolysing potentials, while the application of PEG leads more to particle coalescence. Ostwald ripening seems to appear only at high applied (H 2 forming) potentials in case of the three afore-mentioned ligands while in case of citrate it becomes significant already at mild (CO forming) voltages. By studying the effects of capping agent removal and exchange we demonstrate that apart from ligands directly attached to the Ag NPs, also the excess of capping agents (adsorbed on the electrode surface) plays a decisive role in determining the extent and mode of catalyst degradation. The results of SEM-based particle sizing are also confirmed by synchrotron based wide-angle X-ray scattering measurements that provide further insight into the evolution of crystallite size and lattice strain in the applied Ag NPs during electrolysis. [ABSTRACT FROM AUTHOR]

The Ag@Cu 2 O heterostructure core-shell nanostructure can achieve the sterilization of reactive oxygen groups under visible light. [Display omitted] Marine biological fouling has always been a hot research topic. In this study, silver @ cuprous oxide (Ag@Cu 2 O) core-shell nanoparticles were synthesized via in-situ synthesis method and developed an outstanding antibacterial activity. The bacteriostasis efficiency of Ag@Cu 2 O reached to 99% and 98% against Staphylococcus aureus and Pseudomonas aeruginosa , respectively. The minimum inhibitory concentration of Ag@Cu 2 O decreased from 113.6 μg/mL to 56.8 μg/mL compared with Cu 2 O. Ag@Cu 2 O had better antibacterial activity than Cu 2 O with lower content of Cu 2 O and was more environment friendly. The heterostructure formed at the interface between Ag and Cu 2 O promoted the separation and diffusion of photogenerated electron-hole pairs through the charge transfer channel and promoted the generation of reactive oxygen species. The outstanding antibacterial activity of Ag@Cu 2 O was strongly depended on the generation of the reactive oxygen species. Density functional theory and finite element method calculations demonstrated that the structure of core-shell improved photocatalytic efficiency. Additionally, synergetic effect of released Ag+ and Cu2+ also enhanced the bacteriostasis rate and the long-term antifouling performance in 60 days. Hence, the synthesized core-shell Ag@Cu 2 O can be applied as novel antifoulants in the marine field. [ABSTRACT FROM AUTHOR]

The illustration of the process of the PCBDA@AgNPs-MF for antibiofouling water disinfection. [Display omitted] Mature microfiltration (MF) membrane is a low-cost, effective, and promising technology to provide affordable purified water for people living in developing countries. However, the lack of disinfection ability and inherent membrane fouling problems have seriously restricted the large-scale application of conventional MF treatment system in producing safe drinking water. In this work, zwitterionic silver nanoparticles (AgNPs) with surface modification of poly(carboxybetaine acrylate- co -dopamine methacryamide) (PCBDA) copolymers were robustly immobilized onto commercial polyamide MF membrane via mussel-inspired chemistry for water disinfection. The designed microfiltration membrane, named as PCBDA@AgNPs-MF, exhibited integrated properties of high and stable payload of AgNPs, broad-spectrum anti-adhesive and antimicrobial activities, and easy removal of inactivated microbial cells from membrane surface. Ascribing to the synergetic effect of anti-adhesive and antimicrobial features brought by zwitterionic PCBDA@AgNPs, the biofilms growth on polyamide membrane surface was significantly inhibited, which showed potential access to achieve long-term biofouling resistance and maintain water flux for conventional MF membrane. As water disinfection device, these attributes enabled PCBDA@AgNPs-MF to effectively disinfect the model and natural bacteria-contaminated water. [ABSTRACT FROM AUTHOR]

[Display omitted] • Size-dependent activity of DMO hydrogenation over Ag catalysts. • A volcano-shape trend between hydrogenation activity and the Ag particle size. • Step-likes active sites are identified as the dominant active sites. • Electronic properties dominate the performances of <5.3 nm sized Ag catalysts. Ag catalysts are promising for the selective hydrogenation of dimethyl oxalate (DMO) to methyl glycolate (MG), where the size of Ag nanoparticles strongly dominates their catalytic performances. Fundamental understandings on the size dependence, especially at the level of active sites, are still lacking but of great importance for the rational design of Ag-based catalysts for this reaction. Herein, a series of catalysts consisting of Ag nanoparticles sized from 2.9 to 8.8 nm anchored on amine-derivatized mesoporous silica nanospheres (Ag/AS) were synthesized and employed to understand the size-dependent DMO hydrogenation to MG. A volcano-shape trend between the hydrogenation activity and the increasing Ag particle size is observed for the differently sized Ag/AS catalysts, indicating a remarkable size dependence. The origin of the size dependence is further understood based on the cuboctahedron model of Ag nanoparticle, and the step-likes active sites are identified as the dominant ones. Results combining with the X-ray photoelectron spectroscopy, in situ Fourier transform infrared spectroscopy and temperature programmed desorption studies, indicate that the hydrogenation of DMO to MG on Ag/AS catalysts is mainly dominated by the number of active sites when the Ag particle size ≥ 5.3 nm, but by the electronic properties when the Ag particle size < 5.3 nm. The balance between the number of active sites and electronic structure gives rise to a maximal reaction rate in term of apparent TOF on the Ag/AS catalyst with Ag particle size of 5.3 nm. These understandings may guide the design of highly efficient Ag catalysts for the coal-based MG production. [ABSTRACT FROM AUTHOR]