Anchoring Silver Nanoparticles Research Articles

Novel Honeycomb Nanoclay Frameworks With Hemostatic and Antibacterial Properties.

Our laboratory recently developed a new class of high surface area, honeycomb Nanoclay Microsphere Framework absorbents (NMFs) that prompt rapid hemostasis. In the present work, we propose a novel approach to develop antibacterial Topical Hemostatic Agents (THAs) by anchoring silver nanoparticles (AgNPs) onto NMFs. This combination was obtained by a chemical co-reduction approach, followed by freeze-processing, and was shown to ensure stability and on-site delivery of AgNPs, without altering the hemostatic properties of NMFs. Silver-loaded NMFs showed no change in their unique architecture and led to a 55% increase in clot strength, compared to standard control plasma or commercially available THA, and a significant decrease in mean fibrin fiber diameter. Silver nanoparticles were successfully released when solubilized and prevented the growth of both Pseudomonas aeruginosa and Staphylococcus aureus at concentrations of 22 and 30 ppm of silver released, respectively. Overall, cell mortality was between 9.1 ± 5.1% and 6.3 ± 3.2%, depending on AgNP concentration, confirming a low cytotoxicity. Silver-loaded nanoclay microsphere frameworks appear to constitute promising candidates as topical hemostatic agents for secondary management of hemostasis when infection control is needed.

Highly selective optical and naked-eye recognition of L-cystine through spectroscopy and development of cellulose paper nano biosensor test strips for the early diagnosis of cystinuria

Accurate sensing of small biomolecules from complex biofluid media remains a challenge due to adverse interaction of metallic salts and other biofluid components. L-cystine is the most important biomarker for the disease cystinuria. Recognition of L-cystine in urine is thus fundamental for the timely detection of cystinuria and related chronic kidney disease (CKD). Poor solubility of L-cystine offer limits to design suitable sensors. Herein, we report the synthesis of thioglycolated-β-CD (TG-β-CD) anchored silver nanoparticles (AgNP) as a potential receptor (TG-β-CD⊃AgNP) for the effective optical recognition and quantification of L-cystine through UV–Vis and SERS (surface enhanced Raman spectroscopy) spectroscopic fingerprinting and suitable colourimetric naked-eye detection of L-cystine by indicator displacement assay. Methyl orange (Met-O) indicator was precomplexed with the receptor to generate the probe solution (Met-O@TG-β-CD⊃AgNP). Indicator has been exchanged from Met-O@TG-β-CD⊃AgNP by the addition of L-cystine, with an instantaneous visible colour change from yellow to red. The method is tolerable to other interfering abundant ions and biomolecules. Based on the innovative sensing assay a cellulose paper-dye test strip is developed for point-of-care detection and quantification of the biomarker. Structures of TG-β-CD, TG-β-CD⊃AgNP and Met-O@TG-β-CD⊃AgNP were elucidated by UV–Vis, FT-IR, PXRD, 1H NMR, etc. spectroscopy. Scanning electron microscopy (SEM) was used to examine the morphology of TG-β-CD, AgNP and TG-β-CD⊃AgNP. The chemical changes during the assay were evaluated by conductance, UV–Vis and SERS. The competitive displacement of the indicator and UV turn-on at ppm level analyte concentration made the process compatible for day-to-day point-of-care units.

Coordination engineering of defective F and N co-doped carbon dots anchored silver nanoparticles for boosting oxygen reduction reaction

The carbon-based catalysts exhibit excellent electrocatalytic and stable performance toward oxygen reduction reaction (ORR), which are expected to replace expensive and scarce Pt-based catalysts. However, how to regulate the interaction between silver and carrier carbon dots (CD) to improve electrocatalytic performance toward oxygen reduction reaction (ORR) and stability, has not been systematically studied. In this study, we in-situ synthesized fluorine and nitrogen co-doped CD anchoring Ag nanoparticles by UV irradiation reduction method. The peak potential, onset-potential and half-wave potential of F, N-CD@Ag-0.1 are 0.85 V, 1.056 V, and 0.9 V, respectively, indicating outstanding ORR performance. The current density of F, N-CD@Ag-0.1 remains 97.5 % after 50, 000 s, showing more excellent stability than Pt/C. The impressive ORR catalytic activity and stability of F, N-CD@Ag-0.1 could be attributed to the strong anchoring effect of nitrogen-doped CD on Ag. This effect leads to a significant interaction and charge transfer between Ag and CD, thereby enhancing the charge transfer process during the catalytic reaction. This project aims to design a carbon dot/silver composite catalyst with high ORR catalytic performance and favorable stability. The implementation of this project provides good theoretical guidance for the design of carbon nanomaterial-based catalytic systems.

Enhanced functionalization of nonwoven fabric by spray coating AgNPs/CNTs solution prepared by a one-step method

The convergence of nanotechnology and textile engineering has propelled the development and performance enhancement of multifunctional smart materials across various applications. In this study, a one-step method was used to synthesize a multifunctional smart textile by anchoring silver nanoparticles (AgNPs) onto multi-walled carbon nanotubes (CNTs) and spray coating them onto nonwoven fabric. Incorporating CNTs not only enhanced the conductivity, but also improved the heating efficiency of the resulting fabric, which can increases comfort in cold environments through electric heating. The incorporation of AgNPs contributed to the fabric’s photothermal capability. The photothermal conversion efficiency reached 89.7 % under 100 mW/cm2 illumination, resulting in a temperature of 45.0 °C at a current of 1.0 A. The fabric demonstrated exceptional piezoresistive and strain-sensing capabilities with a response time of only 359 ms under a pressure of 3.25 kPa. In addition, the fabric was able to detect subtle physiological signals, such as the wearer’s pulse, finger flexion, and spinal bending while also monitoring environmental humidity in real time. This research not only advances smart textile technology, but also addresses unique challenges to the one-step preparation of CNTs and AgNPs on nonwoven fabric, thus enabling the design and manufacture of innovative materials with tailored functionalities. These advancements will bear significant impacts on electric heating, photothermal applications, and personal wearable strain sensing in textiles.

Plasmon AgNPs/MoS2/ZnO nanorods array ternary heterojunctions enabling high-efficiency solar-light energy utilization for photocatalysis and recyclable SERS detection

BackgroundSurface-enhanced Raman scattering (SERS) has gained widespread use in molecule-level detection benefiting from its high sensitivity, nondestructive data acquisition, and capacity for providing molecular fingerprint information. However, the strong adhesion of target molecules to the substrate (known as the “memory effect”) inherently hinders the reusability of SERS substrates. Research has shown that self-cleaning SERS substrates based on versatile semiconductor materials with SERS enhancement capabilities and solar photocatalytic properties offer an effective platform for the sensitive detection and degradation of harmful molecules. ResultsIn this research, a resuable SERS-active substrate was facilely fabricated by anchoring silver nanoparticles (AgNPs) to the edges of MoS2 nanosheet decorated on ZnO nanorod arrays (NRAs). This innovative design exhibited a remarkable SERS enhancement factor (EF) of 4.6 × 107 and demonstrated significant solar photocatalytic efficiency. Such superior characteristics of ternary plasma heterojunction were ascribable to the synergistic effect of the “Schottky barrier” and “hot spots” between MoS2 and AgNPs, the inherent chemical enhancement proficiency of the MoS2/ZnO NRAs heterojunction, as well as the ultrafast electron transfer within the ternary heterojunction. SignificanceThe developed ternary heterojunction substrate enabled highly sensitive SERS detection of trace amounts of organic molecules. Moreover, this SERS substrate exhibited self-cleaning and recyclability via solar-light-driven photocatalysis. This bifunctional recyclable SERS substrate proved capable of meeting various requirements for routine monitoring of environmental organic pollutants and provided a robust avenue for advancing energy utilization materials that serve as high-performance SERS sensors and catalysts.

Covalent organic frameworks surface-anchored with silver nanoparticles for colorimetric detection of dopamine based on its oxidase-mimicking activity

Sensitive detection of dopamine (DA) is essential for the diagnosis of nervous system diseases. Herein, a nanozyme-based colorimetric platform for DA determination was proposed. Using an imine-type covalent organic framework (COF-TD) as a host matrix, a nanozyme (AgNPs@COF-TD) was fabricated by anchoring silver nanoparticles (AgNPs) on the surface of COF-TD via in situ reduction of silver ions. Various characterization results confirmed the successful synthesis of flower-like AgNPs@COF-TD with surface-anchored AgNPs, which could expose more active sites. The as-prepared AgNPs@COF-TD exhibited satisfactory oxidase-mimicking activity with a low Km, which could catalyze the oxidation of colorless 3,3′,5,5′-tetramethylbenzidine (TMB) to blue oxidized TMB (oxTMB) with significant absorbance at 657 nm. The introduction of DA not only reduced blue oxTMB to colorless TMB but also competed with TMB for the active sites of AgNPs@COF-TD, making a significant decrease in absorbance. Therefore, a label-free sensing strategy based on the oxidase-mimicking activity of AgNPs@COF-TD was successfully established for the colorimetric detection of DA, with a detection limit down to 0.2 μM. The practical applicability of this assay was further validated by analyzing DA-spiked human urine samples. This work provided a facile approach to prepare COF-based nanozymes, and demonstrated their great potential in colorimetric detection and bioanalysis.

Salophen Anchored Silver Nanoparticle as Nanoprobe Designed for Selective Sensing and Antibacterial Activity

AbstractIndeed, considerable efforts have been made in the domain of silver nanoparticles, including the construction and wide‐ranging applications. This work involves the synthesis and characterization of salophen anchored silver nanoparticles (AgNPs), and its utilization for selective detection of Fe2+ and Cu2+ ions in DMSO. These AgNPs were synthesized by the reduction of Ag+ ions with salophen ligand, and were characterized by different techniques which include UV‐visible, fluorescence, FTIR, SEM, EDX, TEM, PXRD, DLS, and zeta potential. The negative zeta potential value of −19.6 mV evidenced the stability of the AgNPs. These AgNPs were found to sense Fe2+ and Cu2+ ions selectively in DMSO solution at various concentrations. Instant color change from olive to brown as well as olive to light olive was observed while detecting Fe2+ and Cu2+ ions by the nanoprobe, respectively. UV‐visible and fluorescence spectroscopic investigations were carried out to establish the sensing ability of the nanoprobe. Additionally, AgNPs revealed promising antibacterial activity selectively against gram‐negative bacteria over gram‐positive bacteria. Thus, our approach opens up a new track to design novel and operative functionalized nanomaterials for real‐life sensing and biomedical applications.

A new MOF@bioactive glass composite reinforced with silver nanoparticles - a new approach to designing antibacterial biomaterials.

Multifunctional materials that combine antimicrobial properties with the ability to stimulate bone formation are needed to overcome the problem of infected bone defects. As a novel approach, a new composite based on bioactive glass nanoparticles in a simple system of SiO2-CaO (BG) coated with NH4[Cu3(μ3-OH)(μ3-4-carboxypyrazolato)3] (Cu-MOF) with additionally anchored silver nanoparticles (AgNPs) was proposed. Ag@Cu-MOF@BG obtained by the spin coating approach in the form of a disc was characterized using PXRD, ATR-FTIR, XPS, ICP-OES, and TEM. Importantly, the material retained its bioactivity, although ion exchange in the bioactive glass administered as a disc is limited. Hydroxyapatite (HA) formation was identified in TEM images after 7 days of immersion of the composite in a physiological-like buffer (pH 7.4, 37 °C). The Cu and Ag contents of Ag@Cu-MOF@BG were as low as 0.013 and 0.018 wt% respectively, but the slow release of the AgNPs ensured its antibacterial nature. Ag@Cu-MOF@BG exhibited antibacterial activity against all tested bacteria (E. coli, S. aureus, P. aeruginosa, and K. pneumoniae) with the diameter of the inhibition zones of their growth between 8 and 10 mm and the reduction index determined to be ≥3. Moreover, the biocompatibility of the new composite has been demonstrated, as shown by cell culture assays with human dermal fibroblasts (HDFs). The results from the migration test also proved that the HDF cell's phenotypic properties were not changed, and the cell adhesion and migration ability were the same as in control indirect assays.

Silver‐anchored dendrimer efficiently Light‐drive conversion of p‐nitrophenol

AbstractEfficient use of solar energy for photocatalytic organic synthesis and degradation of organic matter is one of the most promising ways to solve energy shortage and environmental pollution. Silver/sulfur‐doped polyimide (Ag/SPI) was successfully prepared by anchoring silver nanoparticles on sulfur doped polyimide with dendriform structure by an open‐loop and closed‐loop method. Through the analysis of the structure, morphology and photoelectric properties by different characteristics, it is found that the anchoring of silver nanoparticles greatly reduces the electron‐hole recombination rate of SPI, and the cyclic stability is relatively good, and the electrons generated by photoexcitation can participate in the reduction of p‐nitrophenol more. Therefore, the activity of degradation of organic pollutants was greatly improved under the irradiation of visible light. At 5 minutes, the degradation rate of p‐nitrophenol reached 100 %, and the only product p‐nitrophenol was generated. The reaction time was 12 times that of SPI without anchored metal particles. The Ag/SPI dual‐function catalyst provides a new idea for the application of p‐nitrophenol wastewater treatment and the conversion of p‐aminophenol and provides a new reference direction for the field of organic wastewater treatment and organic synthesis.

A novel core-shell heterostructure of zinc oxide/metal-organic frameworks anchored silver nanoparticles for enhanced SERS and photocatalytic performance

Here, a novel well-ordered ZnO rod-flower/zeolitic imidazolate framework-M (ZIF-M, using 5-mercapto-1-methyltetrazole as ligand) core-shell heterostructure (Al/ZnO/ZIF-M, AZZ*) is induced by aluminum (Al) sheet. Subsequently, Ag nanoparticles (AgNPs) are tightly attached to the ZIF-M layer in AZZ* through the strong Ag-N and Ag-S bonds, and a portable bifunctional substrate of Al/ZnO/ZIF-M/Ag (AZZ*Ag) is constructed. The finite difference time domain (FDTD) analysis shows that the AZZ*Ag substrate generates the stronger electromagnetic field intensity than the AZAg. Also, there is a strong synergistic effect among Al, ZnO, ZIF-M and Ag which can effectively facilitate the electron transfer. Importantly, the AZZ*Ag substrate exhibits outstanding SERS response with high sensitivity and selectivity for crystal violet (CV) molecules. The low detection limit (LOD) of CV molecule is 2.81 × 10−11 mol·L−1 with high analysis enhancement factor (AEF) of 1.93 × 106. In addition, AZZ*Ag substrate shows good photocatalytic performance for CV molecules with high degradation efficiency of 97.35% within 105 min, which is 4.72 times that of AZAg. Importantly, the SERS and photocatalytic performance of AZZ*Ag are 4.4 times and 3.09 times those of the Al/ZnO/ZIF-8/Ag (AZZ#Ag, using 2-methylimidazole as ligand), respectively. Moreover, the AZZ*Ag substrate displays excellent stability, good reproducibility, recyclability and uniformity. Thus, the designed portable bifunctional composite exhibits great potential for SERS detection and photocatalytic degradation of other pollutants in environmental wastewater.

Surface Engineering of AgNPs-Decorated Polyetheretherketone.

Metal nanostructure-treated polymers are widely recognized as the key material responsible for a specific antibacterial response in medical-based applications. However, the finding of an optimal bactericidal effect in combination with an acceptable level of cytotoxicity, which is typical for metal nanostructures, prevents their expansion from being more significant so far. This study explores the possibility of firmly anchoring silver nanoparticles (AgNPs) into polyetherether ketone (PEEK) with a tailored surface morphology that exhibits laser-induced periodic surface structures (LIPSS). We demonstrated that laser-induced forward transfer technology is a suitable tool, which, under specific conditions, enables uniform decoration of the PEEK surface with AgNPs, regardless of whether the surface is planar or LIPSS structured. The antibacterial test proved that AgNPs-decorated LIPSS represents a more effective bactericidal protection than their planar counterparts, even if they contain a lower concentration of immobilized particles. Nanostructured PEEK with embedded AgNPs may open up new possibilities in the production of templates for replication processes in the construction of functional bactericidal biopolymers or may be directly used in tissue engineering applications.

Anchoring silver nanoparticles using catechol-derived resins: An efficient and versatile approach for producing durable antimicrobial fabrics

Silver nanoparticles (Ag NPs) are one of the most popular antibacterial agents, but Ag NP-modified antibacterial fabrics often show poor laundering durability owing to the weak binding force of Ag NPs to the fabric. In this work, a hydrothermal synthesis of catechol formaldehyde resins (CFR) and Ag NPs from catechol, hexamethylenetetramine, and AgNO3 was developed, and a kind of coating called Ag/CFR was constructed in situ on the surface of cotton, polyester, polyamide, and their blended fabrics. Micromorphologies and chemical structures of the fabric and Ag/CFR coatings were studied, while the antimicrobial performance and other important properties of the fabrics were also investigated. The studies showed that CFR were generated in the solution and anchored Ag NPs onto the surface of the fabric. All the modified fabrics presented high antimicrobial activity with superior laundering durability, achieving a bacteriostasis and fungistasis rate of 99.99 % against S. aureus, E. coli, and C. albicans, even after 50 laundering cycles. Ag/CFR coatings had little influence on the mechanical properties, air permeability, and feel of the fabric. All the antimicrobial fabrics showed low cytotoxicity to NIH3T3 mouse fibroblasts and contained no residual formaldehyde. This work provides an efficient and versatile approach for producing durable coatings for antimicrobial fabrics, which can be widely applied to clothing, bedding, and decorations.

Interfacial Anchored Sesame Ball-like Ag/C To Guide Lithium Even Plating and Stripping Behavior

Lithium (Li) metal is a candidate anode for the next generation of high-energy density secondary batteries. Unfortunately, Li metal anodes (LMAs) are extremely reactive with electrolytes to accumulate uncontrolled dendrites and to generate unwanted parasitic electrochemical reactions. Much attention has been focused on carbon materials to address these issues. Ulteriorly, the failure mechanism investigation of lithiophilic sites on carbon materials has been not taken seriously. Herein, we design a new type of sesame ball-like carbon sphere (AgNPs@CS, an average diameter of ∼700 nm) with uniformly interfacial anchored silver nanoparticles (AgNPs), which is used as the dendrite-free Li metal anode host. This anchored structure significantly enhances reversible and chemical affinity of Li, effectively inhibiting "dead Li". In addition, the protective effect of the carbon layer can avoid the damage of lithiophilic AgNPs in the carbon matrix. With a plating/striping capacity of 2 mA h cm-2, the AgNPs@CS electrode can be cycled over 2400 h at 0.5 mA cm-2. When the stripping voltage increases to 1 V, the AgNPs@CS electrode also enables excellent cycling stability to achieve over 260 cycles (1 mA cm-2, 1 mA h cm-2) and 130 cycles (2 mA cm-2, 1 mA h cm-2). This material by electrochemical characterization highlights the efficacy of this facile method for developing dendrite-free LMAs.

Titanosilicate ETS‐10 Molecular Sieve Anchored Silver Nanoparticles for Efficient Photocatalytic Degradation of Tetracycline Hydrochloride: Synergetic Effect of H2O2 and Ag/ETS‐10 under Visible Light

AbstractHerein, a facile and effective photocatalytic method for the degradation of the tetracycline hydrochloride (TCH) was proposed. The photocatalyst Ag/ETS‐10 was prepared by photoreduction, using cubic‐structured EST‐10 molecular sieves as the support for the silver nanoparticles. The synthesized photocatalyst Ag/ETS‐10 has small characteristic peaks and a chemical shift of Ag, resulting in a redshift. The results of photocatalytic experiments show that H2O2‐promoted Ag/ETS‐10 exhibits a superior visible‐light photocatalytic performance, and the degradation rate of TCH (50 mg L−1) is up to 94.9 % within 100 min, which is significantly better than pure ETS‐10 (23.9 %) and Ag/ETS‐10 (26.9 %). The reaction rate constant of H2O2‐promoted Ag/ETS‐10 is 17.75 and 31.55 times of those of ETS‐10 and Ag/ETS‐10, respectively. More importantly, the photocatalytic activity of H2O2‐promoted Ag/ETS‐10 remains stable after four cycles. The outstanding photocatalytic performance is due to the synergistic interaction of H2O2 with Ag/ETS‐10 to promote the rapid separation of photo‐generated electron‐hole pairs and enhance the generation of h+ and ⋅O2− radicals. In addition, the presence of silver induces the surface plasmon resonance effect and acts as a good acceptor for photogenerated e− in the photocatalytic reaction, enhancing the photocatalytic activities. This work provides a new insight for the design and synthesis of stable and efficient photocatalysts for visible light degradation of antibiotics.

Anchoring silver nanoparticles on nanofibers by thermal bonding to construct functional surface.

Generally, the anchoring of inorganic nanoparticles onto the surface of fibers faces the problem of poor stability, which limits the wide application of nanoparticle functionalized fibers. Herein, nanofibers with shell-core structures were constructed by coaxial electrospinning of two polymers with different melting points (Tm). Polyglycolic acid (PGA, Tm = 225 °C) was employed as the core layer, while polycaprolactone (PCL, Tm = 60 °C) was used as the shell layer. Silver nanoparticles (AgNPs) were electrosprayed on the nanofibers and the shell layer (PCL) was heated and melted to bond the AgNPs, thus realizing a stable AgNP-composited nanofiber for the construction of antibacterial functional surface. By regulating the shell-core flow ratio and the condition for heat treatment, the appropriate thickness of the shell layer was obtained with a flow ratio of 3:1 (PCL:PGA). The optimal composite structure was constructed when the thermal bonding was taken under 80 °C for 5 min. Furthermore, it was found that the composite nanofibers prepared by thermal bonding had better hydrophilicity, mechanical property, and AgNPs bonding stability, and their antibacterial rate against Staphylococcus aureus (S. aureus) reached over 97%. Overall, a facile and universal method for the preparation of nanoparticle-anchored nanofibers was established in this study. The robust nanoparticle-composited nanofibers are promising for applications in optoelectronic devices, electrode materials, and so on.

Silver doped dodecahedral metal-organic framework anchored RGO nanosheets for nanomolar quantification of priority toxic pollutant in aquatic environment

Detection of hazardous environmental pollutants to maintain safety is a significant concern worldwide. In this work, we developed a reliable and sensitive electrochemical sensor for the effective detection of a priority toxic pollutant, 4-nitrophenol (4NP), in the aquatic environment. A ternary nanocomposite was sonochemically prepared by anchoring silver nanoparticles doped rhombic dodecahedral zeolitic imidazolate framework-67 (ZIF-67) on reduced graphene oxide (RGO) nanosheets. We employed a solvothermal method in the preparation of ZIF-67, and the graphene oxide prepared by the Hummer’s method was chemically reduced using ascorbic acid. Important characterization techniques including XRD, SEM, elemental mapping, TEM, XPS, BET, Raman spectroscopy, FTIR, and EIS were used for evaluating properties of the synthesized nanomaterials. The prepared porous ternary nanocomposite evinced outstanding electrocatalytic activity towards 4NP determination, and the developed 4NP sensor showcased a very low detection limit of 0.3 nM and high sensitivity of 65.49 μAμM−1 cm−2. Furthermore, significant performance criterions, including stability, reproducibility, anti-interference, and repeatability were examined to prove the reliability of the proposed sensor in 4NP quantification. The practical feasibility of the developed 4NP sensor was also evaluated by carrying out experiments with river water, lake water, and underground water samples.

MXene-derived TiO2 nanosheets decorated with Ag nanoparticles for highly sensitive detection of ammonia at room temperature

• A novel AgNPS-anchored Ti 3 C 2 T x MXene–derived TiO 2 nanocomposite is fabricated for high-precision gas sensors. • The Ag@TiO 2 gas sensor exhibited a response value of 71.8 to 50 ppm NH 3 at room temperature with a detection limit of 5 ppm. • Enhanced NH 3 sensing response mechanism of the Ag@TiO 2 nanocomposite is discussed. Due to their large surface-to-volume ratio and low electronic noise, two-dimensional transition metal carbides (Ti 3 C 2 T x MXene) and their derived transition metal oxides have demonstrated significant potential for use in high-precision gas sensing. However, the construction of high-sensitivity Ti 3 C 2 T x MXene–based gas sensors operated at room temperature (RT) is still a major challenge. Herein, we demonstrate a sensitive nanocomposite prepared by uniformly anchoring silver nanoparticles (AgNPs) on Ti 3 C 2 T x MXene–derived transition metal oxide (TiO 2 ) nanosheets for high-sensitivity NH 3 detection. AgNPs can not only serve as spacers to effectively prevent the restacking of MXene-derived TiO 2 nanosheets and ensure an effective transmission highway for target gas molecules, but also enhance the sensitivity of the sensor through chemical and electronic sensitization. By integrating the unique merits of the individual components and the synergistic effects of the composites, the optimized Ag@TiO 2 nanocomposite–based sensors revealed an extraordinary response value of 71.8 to 50 ppm NH 3 at RT with a detection limit as low as 5 ppm. In addition, the Ag@TiO 2 NH 3 sensor also exhibits excellent selectivity and outstanding repeatability. This strategy provides an avenue for the development of MXene derivatives for advanced gas sensors.

Anchoring Silver Nanoparticles Using Catechol Derived Resins: An Efficient and Versatile Approach to Durable Antimicrobial Fabrics

Anchoring Silver Nanoparticles Using Catechol Derived Resins: An Efficient and Versatile Approach to Durable Antimicrobial Fabrics

A sandwich structure composite wound dressing with firmly anchored silver nanoparticles for severe burn wound healing in a porcine model.

Wounds may remain open for a few weeks in severe burns, which provide an entry point for pathogens and microorganisms invading. Thus, wound dressings with long-term antimicrobial activity are crucial for severe burn wound healing. Here, a sandwich structure composite wound dressing anchored with silver nanoparticles (AgNPs) was developed for severe burn wound healing. AgNPs were in situ synthesized on the fibers of chitosan nonwoven fabric (CSNWF) as the interlayer of wound dressing for sustained release of silver ion. The firmly anchored AgNPs could prevent its entry into the body, thereby eliminating the toxicity of nanomaterials. The outer layer was a polyurethane membrane, which has a nanoporous structure that could maintain free transmission of water vapor. Chitosan/collagen sponge was selected as the inner layer because of its excellent biocompatibility and biodegradability. The presence of AgNPs in the CSNWF was fully characterized, and the high antibacterial activity of CSNWF/AgNPs was confirmed by against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. The superior wound healing effect on deep dermal burns of presented composite wound dressing was demonstrated in a porcine model. Our finding suggested that the prepared AgNPs doped sandwich structure composite wound dressing has great potential application in severe wound care.

Silver Nanowire Network Hybridized with Silver Nanoparticle-Anchored Ruthenium Oxide Nanosheets for Foldable Transparent Conductive Electrodes.

Facile strategies in flexible transparent conductive electrode materials that can sustain their electrical conductivities under 1 mm-scale radius of curvature are required for wider applications such as foldable devices. We propose a rational design as well as a fabrication process for a silver nanowire-based transparent conductive electrode with low sheet resistance and high transmittance even after prolonged cyclic bending. The electrode is fabricated on a poly(ethylene terephthalate) film through the hybridization of silver nanowires with silver nanoparticles-anchored RuO2 nanosheets. This hybridization significantly improves the performance of the silver nanowire network under severe bending strain and creates an electrically percolative structure between silver nanowires and RuO2 nanosheets in the presence of anchored silver nanoparticles on the surface of RuO2 nanosheets. The resistance change of this hybrid transparent conductive electrode is 8.8% after 200,000 bending cycles at a curvature radius of 1 mm, making it feasible for use in foldable devices.