Combination Of Ag Nanoparticles Research Articles

Reduced graphene oxide-based sensor for triamcinolone acetonide detection: Advancements in doping agent surveillance for athletes

The use of performance-enhancing drugs in sports is a major concern for athletes, coaches, and sports organizations. To address this issue, researchers have been developing advanced doping agent surveillance techniques, including the use of sensors for detecting prohibited substances in athletes' samples. The aim of this work was to create Ag nanoparticles and a reduced graphene oxide paste electrode (Ag-rGOPE) that could be used as an electrochemical sensor to measure the amounts of triamcinolone acetonide (TAA) in athlete blood serum samples for the purpose of detecting doping. The combination of Ag nanoparticles on rGO nanosheets was validated by the findings of structural investigations. The potential of Ag-rGOPE as a promising substitute for the analysis of TAA in actual samples was underlined by the electrochemical investigations. Ag-rGOPE was reported to have a sensitivity value of 0.67522 μA/μM, a linear range of 10 to 300 μM, and a limit of detection of 0.005 μM. High electrochemical reactivity, a broad linear range, and a small limit of detection were all characteristics of the Ag-rGOPE toward TAA. With considerable recovery values (above 96.00 %) and acceptable precision (RSD less than 4.37 %), the sensor showed outstanding performance for detecting TAA in serum samples. Overall, Ag-rGOPE demonstrated potential as an electrochemical sensor for measuring TAA levels in athlete serum samples that is both dependable and accurate.

Difunctional Ag nanoparticles with high lithiophilic and conductive decorate on core-shell SiO2 nanospheres for dendrite-free lithium metal anodes

Lithium metal is an attractive and promising anode material due to its high energy density and low working potential. However, the uncontrolled growth of lithium dendrites during repeated plating and stripping processes hinders the practical application of lithium metal batteries, leading to low Coulombic efficiency, poor lifespan, and safety concerns. In this study, we synthesized highly lithiophilic and conductive Ag nanoparticles decorated on SiO2 nanospheres to construct an optimized lithium host for promoting uniform Li deposition. The Ag nanoparticles not only act as lithiophilic sites but also provide high electrical conductivity to the Ag@SiO2@Ag anode. Additionally, the SiO2 layer serves as a lithiophilic nucleation agent, ensuring homogeneous lithium deposition and suppressing the growth of lithium dendrites. Theoretical calculations further confirm that the combination of Ag nanoparticles and SiO2 effectively enhances the adsorption ability of Ag@SiO2@Ag with Li+ ions compared to pure Ag and SiO2 materials. As a result, the Ag@SiO2@Ag coating, with its balanced lithiophilicity and conductivity, demonstrates excellent electrochemical performance, including high Coulombic efficiency, low polarization voltage, and long cycle life. In a full lithium metal cell with LiFePO4 cathode, the Ag@SiO2@Ag anode exhibits a high capacity of 133.1 and 121.4 mAh/g after 200 cycles at rates of 0.5 and 1C, respectively. These results highlight the synergistic coupling of lithiophilicity and conductivity in the Ag@SiO2@Ag coating, providing valuable insights into the field of lithiophilic chemistry and its potential for achieving high-performance batteries in the next generation.

Photothermally Triggered Control of the Drug Delivery System Using Doxorubicin-Loaded Mesoporous Silica for Effective Killing of Human Hepatoma Cells

Photothermal-temperature responsive [Ag nanoparticles-hollow mesoporous silica nanospheres–poly (N-isopropyl acrylamide-acrylic acid)] (Ag@HMSN@PNIPAM-AA) nanoparticles were designed and prepared, and the combination of Ag nanoparticles (AgNPs) and [poly (N-isopropyl acrylamide-acrylic acid)] (PNIPAM-AA) was used as a switch of the photothermal-temperature effect to control drug release. The results of cell culture in vitro showed that [mesoporous silica nanospheres–poly (N-isopropyl acrylamide-acrylic acid)] (MSN@PNIPAM-AA) and Ag@HMSN@PNIPAM-AA nanoparticles had good biocompatibility and less cytotoxicity, and Ag@HMSN@PNIPAM-AA nanoparticles had higher cell inhibition under 808 nm near-infrared light. The combination of near-infrared light and doxorubicin showed higher drug release efficiency and a stronger inhibitory effect on HepG2 cell growth. These characteristics indicate that Ag@HMSN@PNIPAM-AA nanoparticles have great potential for treatment. This study also proved the universal applicability of Ag@HMSN@PNIPAM-AA nanoparticles. Different model drugs and nanoparticles can play different roles and have development potential.

Simulation of Mushroom Nanostructures with Ag Nanoparticles for Broadband and Wide-Angle Superabsorption

Metal nanoparticles (NPs) concentrate the energy of incident photons through plasmon resonance excitation, which allows scattering into a substrate with a high refractive index, and the radiated energy from this excitation significantly increases the optical absorption of the substrate. In this work, the effect of Ag NPs on the absorption capacity of mushroom-nanostructured Si metasurfaces was analyzed using the finite-difference time-domain method. It was observed that the absorbance in the metasurfaces with Ag NPs increased from 90.8% to 98.7% compared with nanostructured Si metasurface without NPs. It was shown that the plasmon resonance effect of Ag NPs enlarged the range of the FP cavity by about 10 times, and the electric field strength E2 increased by about four times through the combination of Ag NP and Si absorbers. Meanwhile, the effect of randomly distributed nanostructures on the absorption properties of Si metasurfaces was simulated. Additionally, the nanostructured surface with Ag NPs was insensitive to angle, which encourages the design of broadband and wide-angle superabsorption nanostructures.

Different concepts for creating antibacterial yet biocompatible surfaces: Adding bactericidal element, grafting therapeutic agent through COOH plasma polymer and their combination

Antibacterial coatings have become a rapidly developing field of research, strongly stimulated by the increasing urgency of identifying alternatives to the traditional administration of antibiotics. Such coatings can be deposited onto implants and other medical devices and prevent the inflammations caused by hospital-acquired infections. Nevertheless, the design of antibacterial yet biocompatible and bioactive surfaces is a challenge that biological community has faced for many years but the “materials of dream” have not yet been developed. In this work, the biocompatible yet antibacterial multi-layered films were prepared by a combination of magnetron sputtering (TiCaPCON film), ion implantation (Ag-doped TiCaPCON film), plasma polymerization (COOH layer), and the final immobilization of gentamicin (GM) and heparin (Hepa) molecules. The layer chemistry was thoroughly investigated by means of FTIR and X-ray photoelectron spectroscopies. It was found that the immobilization of therapeutic components occurs throughout the entire thickness of the plasma-deposited COOH layer. The influence of each type of bactericide (Ag+ ions, GM, and Hepa) on antibacterial activity and cell proliferation was analyzed. Our films were cytocompatible and demonstrated superior bactericidal efficiency toward antibiotic-resistant bacterial E. coli K261 strain. Increased toxicity while using the combination of Ag nanoparticles and COOH plasma polymer is discussed.

Metal and bimetallic nanoparticles: Flow synthesis, bioactivity and toxicity

HypothesisMetal nanoparticles are used as additives in commercial products due to their antimicrobial properties. Apart from their high biocidal activity, it is widely observed that silver nanoparticles are toxic. Simultaneously, copper nanoparticles show fungicidal properties, but with limited effectiveness. Hence, it is suggested that a combination of Ag nanoparticles with Cu nanoparticles may decrease the toxic effects of silver while maintaining their high bioactivity. ExperimentsThis paper presents the properties of Ag and Cu metal nanoparticles, and Ag-Cu and Cu-Ag bimetallic nanoparticles, synthesised in a continuous microwave reactor. The size of the metal nanoparticles obtained was in the range of 27–97 nm, and the size of the bimetallic nanoparticles was in the range of 32–184 nm, depending on the microwave irradiation, residence time, pH of the solution and concentrations of the reagents. FindingsSilver nanoparticles of particle size 97 nm revealed the highest antimicrobial activity (MIC = 10 mg/dm3). Simultaneously, silver nanoparticles did not show viral properties, compared to the copper and bimetallic nanoparticles, for which the virus titre was 1.06–1.50 log TCID50/cm3. In contrast to pure metal nanoparticles, the combination of silver and copper in bimetallic systems generated nanoparticles with no genotoxicity (rac(-)/rac(+) < 1.2).

Ag/Fe3O4 nanocomposites penetrate and eradicate S. aureus biofilm in an in vitro chronic wound model

Bacterial biofilms are a common cause of the persistence of chronic wounds, and continue to be an unsolved problem in infection microbiology due to their tolerance to antibiotics. Silver nanoparticles (Ag-NPs) have attracted attention as an alternative to antibiotics for treatment of wound infections, but their use is challenged by limited tissue penetration and high cytotoxicity. The aim of this study was to show that combination of Ag nanoparticles with Fe3O4 to produce Ag/Fe3O4 nanocomposites (NCs) can overcome these problems, as they penetrate and eradicate biofilms when applying a magnetic field. Ag/Fe3O4-NCs were synthesized using starch as a stabilizer and linker between Ag and Fe3O4 NPs, resulting in agglomerations of 20 nm Ag-NPs and 5 nm Fe3O4 NPs. The antibacterial activity was evaluated against an in vitro chronic wound biofilm model, and cytotoxicity was evaluated on human fibroblasts. Increasing the amount of starch during synthesis led to formation of NCs with increased antibacterial activity. In comparison to Ag-NPs, the NCs showed lower Ag+ release, less ROS production, were less cytotoxic, but nevertheless, their antimicrobial efficacy was higher. Furthermore, their efficiency against biofilm could be enhanced by applying a magnetic field, which ensured penetration of the entire biofilm. In conclusion, Ag/Fe3O4-NCs display important advantages over Ag-NPs as a potential avenue for development of novel therapeutic strategies for treatment of chronic wound infections.

Silver nanoparticles embedded boron-doped reduced graphene oxide as anode material for high performance lithium ion battery

Lithium ion batteries (LIBs) are important energy generation and storage devices and the development of anode materials can improve the electrochemical performance of LIBs. Herein, we report the fabrication of Ag nanoparticles embedded boron-doped reduced graphene oxide (Ag/B-rGO) with the addition of 10–30 wt% boric acid as anode materials for high performance LIB application. The combination of Ag nanoparticles with B-doped rGO enhances the reactivity of nanocomposites toward Li+ ions intercalation. The Ag/B-rGO nanocomposites with the addition of 30 wt% boric acid (Ag/B-rGO-30) exhibits significantly improved rate capability. The reversible capacity of 1484 mAh g−1 at 50mAg−1 is initially observed and can retain at 430 mAh g−1 when the current density increases to 1000mAg−1. In addition, the Ag/B-rGO exhibits the stable capacity of 540 mAh g−1 at 100mAg−1 after 100 cycles of lithiation/delithiation process. The presence of doped boron improves the electron density and increases the defect sites, resulting in the acceleration of electron transfer rate through the graphitic network. In addition, the embedded Ag nanoparticles with diameters of 10–15nm over 2–3 layered B-rGO decrease the internal resistance of Ag/B-rGO nanocomposites as well as improve the conductively nano-dimensional contacts for electron transport. Results obtained in this study clearly demonstrate the role of heteroatoms in the enhancement of electrochemical performance of lithiation capacity and can open a new route to fabricate metal-decorated rGO-based nanomaterials for high performance energy storage devices.

Silver-loaded nanotubular structures enhanced bactericidal efficiency of antibiotics with synergistic effect in vitro and in vivo.

Antibiotic-resistant bacteria have become a major issue due to the long-term use and abuse of antibiotics in treatments in clinics. The combination therapy of antibiotics and silver (Ag) nanoparticles is an effective way of both enhancing the antibacterial effect and decreasing the usage of antibiotics. Although the method has been proved to be effective in vitro, no in vivo tests have been carried out at present. Herein, we described a combination therapy of local delivery of Ag and systemic antibiotics treatment in vitro in an infection model of rat. Ag nanoparticle-loaded TiO2 nanotube (NT) arrays (Ag-NTs) were fabricated on titanium implants for a customized release of Ag ion. The antibacterial properties of silver combined with antibiotics vancomycin, rifampin, gentamicin, and levofloxacin, respectively, were tested in vitro by minimum inhibitory concentration (MIC) assay, disk diffusion assay, and antibiofilm formation test. Enhanced antibacterial activity of combination therapy was observed for all the chosen bacterial strains, including gram-negative Escherichia coli (ATCC 25922), gram-positive Staphylococcus aureus (ATCC 25923), and methicillin-resistant Staphylococcus aureus (MRSA; ATCC 33591 and ATCC 43300). Moreover, after a relative short (3 weeks) combinational treatment, animal experiments in vivo further proved the synergistic antibacterial effect by X-ray and histological and immunohistochemical analyses. These results demonstrated that the combination of Ag nanoparticles and antibiotics significantly enhanced the antibacterial effect both in vitro and in vivo through the synergistic effect. The strategy is promising for clinical application to reduce the usage of antibiotics and shorten the administration time of implant-associated infection.

Liquid Marbles Stabilized by Fluorine-Bearing Cyclomatrix Polyphosphazene Particles and Their Application as High-Efficiency Miniature Reactors.

Increasing attention has been paid to fabricate multifunctional stabilizers of liquid marbles for expanding their application. Here, a kind of hydrophobic cyclomatrix polyphosphazene particles (PZAF) were facilely prepared using a one-step precipitation polycondensation of hexachlorocyclotriphosphazene and 4,4'-(hexafluoroisopropylidene)diphenol, and their ability to stabilize liquid marbles was first investigated. The Ag nanoparticle-decorated PZAF particles (Ag/PZAF) were then fabricated by an in situ reduction of silver nitrate onto PZAF particles and used to construct catalytic liquid marbles. The results revealed that the reduction of methylene blue (MB) in aqueous solution by sodium borohydride could be highly efficiently catalyzed in the catalytic liquid marbles, even with a large volume. An excellent cycle use performance of the catalytic liquid marbles without losing catalytic efficiency was also present. The high catalytic activity is mainly attributed to the uniform immobilization of Ag nanoparticles onto PZAF particles and the adsorption behavior of PZAF particles toward MB, which may play an effect on allowing high catalytic surface area and effective accelerating the mass transfer of MB to the Ag catalytic active sites, respectively. Therefore, the combination of Ag nanoparticles with PZAF particles has been demonstrated clearly to be a facile and effective strategy to obtain the functional stabilizer for preparing the catalytic liquid marbles as promising miniature reactors used in heterogeneous catalytic reactions.

PVP-Assisted Synthesis and Enhanced Photocatalytic Activity of Ag/Ag&lt;sub&gt;3&lt;/sub&gt;PO&lt;sub&gt;4 &lt;/sub&gt;Composites

In the present work, a highly active visible-light-driven Ag/Ag3PO4 photocatalyst was synthesized through a simple poly (vinylpyrrolidone) (PVP)-assisted precipitation method. It was found that the photodegradation activity of RhB over Ag/ Ag3PO4 is superior to pure Ag3PO4 due to the combination of Ag nanoparticles. Study of the photocatalytic mechanism revealed that the degradation of RhB under visible light irradiation over the as-prepared Ag/Ag3PO4 is mainly via the direct hole oxidation mechanism. The Ag/Ag3PO4 photocatalyst keeps a high level of activity even though it is used for five times.

Combined Effects of Ag Nanoparticles and Oxygen Plasma Treatment on PLGA Morphological, Chemical, and Antibacterial Properties

The purpose of this study is to investigate the combined effects of oxygen plasma treatments and silver nanoparticles (Ag) on PLGA in order to modulate the surface antimicrobial properties through tunable bacteria adhesion mechanisms. PLGA nanocomposite films, produced by solvent casting with 1 wt % and 7 wt % of Ag nanoparticles were investigated. The PLGA and PLGA/Ag nanocomposite surfaces were treated with oxygen plasma. Surface properties of PLGA were investigated by field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), static contact angle (CA), and high resolution X-ray photoelectron spectroscopy (XPS). Antibacterial tests were performed using an Escherichia coli RB (a Gram negative) and Staphylococcus aureus 8325-4 (a Gram positive). The PLGA surface becomes hydrophilic after the oxygen treatment and its roughness increases with the treatment time. The surface treatment and the Ag nanoparticle introduction have a dominant influence on the bacteria adhesion and growth. Oxygen-treated PLGA/Ag systems promote higher reduction of the bacteria viability in comparison to the untreated samples and neat PLGA. The combination of Ag nanoparticles with the oxygen plasma treatment opens new perspectives for the studied biodegradable systems in biomedical applications.

Synthesis of confined Ag nanowires within mesoporous silica via double solvent technique and their catalytic properties

Ag nanowires within the channels of mesoporous silica have been successfully synthesized via a double solvent technique, in which n-hexane is used as a hydrophobic solvent to disperse mesoporous silica and an AgNO3 aqueous solution is used as a hydrophilic solvent to fill mesochannels. The morphology of the obtained Ag (nanowires, nanoparticles or nanorods) can be controlled by adjusting the concentration of AgNO3 solution and the template pore size. HRTEM images demonstrate extensive Ag nanowires with several to tens of hundreds nanometers in length are deposited along the long axis of mesochannels when the atomic AgNO3/Si ratio is 0.090. When the atomic AgNO3/Si ratio is 0.068 or 0.11, there is a combination of Ag nanoparticles and nanowires; nanoparticles are mainly formed when the atomic AgNO3/Si ratio is higher than 0.14. Further, the catalytic results of the oxidation of styrene show that styrene oxide and benzaldehyde are the main products of the reaction, and the morphology and diversity of Ag in Ag/mesoporous silica composites have an effect on the conversion of styrene and selectivity of styrene oxide.

Carbon nanotubes and silver nanoparticles for multifunctional conductive biopolymer composites

This article fabricates and characterizes the combination of single walled carbon nanotubes (SWCNTs) and silver nanoparticles (Ag) with a biodegradable polymer matrix. Different SWCNT amount were mixed with Ag nanoparticles and introduced in the poly(ε-caprolactone) (PCL) polymer matrix by solvent cast process. Nanostructure synergistic effects were evaluated in terms of morphological, electrical, dielectrical, mechanical and biological properties of binary PCL/Ag, PCL/SWCNTs and ternary PCL/Ag/SWCNTs composites. Results showed a good dispersion of nanostructures in the PCL and an increase of Young modulus with silver content in the binary systems. The PCL/Ag composites exhibited poor electrical properties, while in PCL/Ag/SWCNTs ternary films higher values of conductivity were measured compared to both binary composites. Results obtained in this research indicate that Ag particles facilitate the formation of conductive pathways in the presence of SWCNTs, they act as conductive bridges among nanotube bundles and facilitate the electron transfer. The addition of a small percentage of SWCNTs promoted significantly the electrical properties of PCL/Ag nanohybrid films. Biocompatibility of binary and ternary composites, evaluated by human mesenchymal stem cells-bone marrow derived (hBM-MSCs), suggests that the combination of Ag nanoparticles and SWCNTs with a biodegradable polymer opens new perspectives for biomedical applications.