Silver nanoparticles for printable electronics and biological applications

2009 ◽  
Vol 24 (9) ◽  
pp. 2828-2836 ◽  
Author(s):  
Krishna Balantrapu ◽  
Dan V. Goia

An environmentally friendly route to prepare stable concentrated aqueous dispersions of silver nanoparticles is described. It was found that Arabic gum, a well known stabilizing agent, can also rapidly and completely reduce Ag2O to metallic silver in alkaline solutions (pH > 12.0) and elevated temperature (65 °C). The average size of the silver nanoparticles could be tailored from 10 to 30 nm by varying the experimental conditions. By hydrolyzing either enzymatically or chemically the polysaccharide, it was possible to isolate dispersed silver nanoparticles suitable for both biological and printable electronics applications. For the latter purpose, concentrated dispersions of silver particles were prepared and used for depositing thin uniform layers, which could be sintered into conductive films at low temperatures.

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2551
Author(s):  
Mateusz Dulski ◽  
Katarzyna Malarz ◽  
Michał Kuczak ◽  
Karolina Dudek ◽  
Krzysztof Matus ◽  
...  

To solve the problem of human diseases caused by a combination of genetic and environmental factors or by microorganisms, intense research to find completely new materials is required. One of the promising systems in this area is the silver-silica nanocomposites and their derivatives. Hence, silver and silver oxide nanoparticles that were homogeneously distributed within a silica carrier were fabricated. Their average size was d = (7.8 ± 0.3) nm. The organic polymers (carboxymethylcellulose (CMC) and sodium alginate (AS)) were added to improve the biological features of the nanocomposite. The first system was prepared as a silver chlorine salt combination that was immersed on a silica carrier with coagulated particles whose size was d = (44.1 ± 2.3) nm, which coexisted with metallic silver. The second system obtained was synergistically interacted metallic and oxidized silver nanoparticles that were distributed on a structurally defective silica network. Their average size was d = (6.6 ± 0.7) nm. Physicochemical and biological experiments showed that the tiny silver nanoparticles in Ag/SiO2 and Ag/SiO2@AS inhibited E. coli, P. aeruginosa, S. aureus, and L. plantarum’s cell growth as well as caused a high anticancer effect. On the other hand, the massive silver nanoparticles of Ag/SiO2@CMC had a weaker antimicrobial effect, although they highly interacted against PANC-1. They also generated reactive oxygen species (ROS) as well as the induction of apoptosis via the p53-independent mechanism.


Author(s):  
Sergey A. Vorobyev ◽  
Maksim N. Likhatski ◽  
Alexander S. Romanchenko ◽  
Timur Y. Ivanenko ◽  
Diana A Masharova ◽  
...  

The reaction of reduction solution of Ag (I) by Fe (II) citrate complex was studied herein. This allows you to receive silver nanoparticles with high stability with a concentration above 60 g/l. It was determined that the nanoparticles size depends on the injection rate, mixing rate, reagent concentration, pH and some post-synthetic operations on the average size of nanoparticles. It was shown that decreasing the concentration of Ag (I) and increasing the concentration of stabilizer also bringing pH to 7 lead to small and uniform particles. Optimal conditions were found that made it possible to reduce particle size and reduce the concentration of reagents by 33 % in the results. According to XPS, TEM, DLS and FTIR datas, nanoparticles of metallic silver with a size of 6.5±1.8 nm were obtained, which stabilized by the product of partial decay of the citrate ion


Author(s):  
M. Linga Rao ◽  
Bhumi G ◽  
Savithramma N

Silver nanoparticles (SNPs) exhibit tremendous applications in medicine as antimicrobial agent.  The use of different parts of plants for the synthesis of nanoparticles is considered as a green technology as it does not involve any harmful chemicals.  In the present study, we report a rapid biosynthesis of silver nanoparticles from aqueous leaf extract of medicinal plant Allamanda cathartica.  The active phytochemicals present in the plant were responsible for the quick reduction of silver ion to metallic silver nanoparticles. The reduced silver nanoparticles were characterized by using UV-Vis spectrophotometry, Scanning Electron Microscope (SEM), Energy Dispersive Analysis of X-ray (EDAX) and Atomic Force Microscopy (AFM).  The spherical shaped silver nanoparticles were observed and it was found to 19-40 nm range of size.  These phytosynthesized SNPs were tested for their antimicrobial activity and it analyzed by measuring the inhibitory zone. A. cathartica aqueous leaf extract of SNPs showed highest toxicity to Pseudomonas followed by Klebsiella, Bacillus and E. coli and lowest toxicity towards Proteus. In fungal species, highest inhibition zone was noted against Rhizopus followed by Curvularia, Aspergillus flavus and Aspergillus niger and minimum inhibition zone was observed against Fusarium species.  These results suggest a promising potential of Indian plant-based green chemistry for production of SNPs for biomedical and nanotechnology applications.


Biology ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 473
Author(s):  
Prabu Kumar Seetharaman ◽  
Rajkuberan Chandrasekaran ◽  
Rajiv Periakaruppan ◽  
Sathishkumar Gnanasekar ◽  
Sivaramakrishnan Sivaperumal ◽  
...  

To develop a benign nanomaterial from biogenic sources, we have attempted to formulate and fabricate silver nanoparticles synthesized from the culture filtrate of an endophytic fungus Penicillium oxalicum strain LA-1 (PoAgNPs). The synthesized PoAgNPs were exclusively characterized through UV–vis absorption spectroscopy, Fourier Transform Infra-Red spectroscopy (FT-IR), X-ray powder diffraction (XRD), and Transmission Electron Microscopy (TEM) with energy dispersive X-ray spectroscopy (EDX). The synthesized nanoparticles showed strong absorbance around 430 nm with surface plasmon resonance (SPR) and exhibited a face-centered cubic crystalline nature in XRD analysis. Proteins presented in the culture filtrate acted as reducing, capping, and stabilization agents to form PoAgNPs. TEM analysis revealed the generation of polydispersed spherical PoAgNPs with an average size of 52.26 nm. The PoAgNPs showed excellent antibacterial activity against bacterial pathogens. The PoAgNPs induced a dose-dependent cytotoxic activity against human adenocarcinoma breast cancer cell lines (MDA-MB-231), and apoptotic morphological changes were observed by dual staining. Additionally, PoAgNPs demonstrated better larvicidal activity against the larvae of Culex quinquefasciatus. Moreover, the hemolytic test indicated that the as-synthesized PoAgNPs are a safe and biocompatible nanomaterial with versatile bio-applications.


Author(s):  
Gattu Sampath ◽  
Muthusamy Govarthanan ◽  
Neelamegam Rameshkumar ◽  
Dai-Viet N. Vo ◽  
Muthukalingan Krishnan ◽  
...  

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 783
Author(s):  
Fulvio Di Lorenzo ◽  
Kay Steiner ◽  
Sergey V. Churakov

Precipitation of calcium carbonates in aqueous systems is an important factor controlling various industrial, biological, and geological processes. In the first part of this study, the well-known titration approach introduced by Gebauer and coworkers in 2008 s used to obtain reliable experimental dataset for the deep understanding of CaCO3 nucleation kinetics in supersaturated solutions over a broad range of pH and ionic strength conditions. In the second part, the effect of impurities, i.e., 1 mol% of Pb2+, was assessed in the same range of experimental conditions. Divalent lead has been shown to have an inhibitory effect in all ranges of the conditions tested except for pH 8 and low ionic strength (≤0.15 mol/L). Future investigations might take advantage of the methodology and the data provided in this work to investigate the effect of other system variables. The investigation of all the major variables and the assessment of eventual synergic effects could improve our ability to predict the formation of CaCO3 in complex natural systems.


Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3790
Author(s):  
Pratama Jujur Wibawa ◽  
Muhammad Nur ◽  
Mukhammad Asy’ari ◽  
Wijanarka Wijanarka ◽  
Heru Susanto ◽  
...  

This research aimed to enhance the antibacterial activity of silver nanoparticles (AgNPs) synthesized from silver nitrate (AgNO3) using aloe vera extract. It was performed by means of incorporating AgNPs on an activated carbon nanoparticle (ACNPs) under ultrasonic agitation (40 kHz, 2 × 50 watt) for 30 min in an aqueous colloidal medium. The successful AgNPs synthesis was clarified with both Ultraviolet-Visible (UV-Vis) and Fourier Transform Infrared (FTIR) spectrophotometers. The successful AgNPs–ACNPs incorporation and its particle size analysis was performed using Transmission Electron Microscope (TEM). The brown color suspension generation and UV-Vis’s spectra maximum wavelength at around 480 nm confirmed the existence of AgNPs. The particle sizes of the produced AgNPs were about 5 to 10 nm in the majority number, which collectively surrounded the aloe vera extract secondary metabolites formed core-shell like nanostructure of 8.20 ± 2.05 nm in average size, while ACNPs themselves were about 20.10 ± 1.52 nm in average size formed particles cluster, and 48.00 ± 8.37 nm in average size as stacking of other particles. The antibacterial activity of the synthesized AgNPs and AgNPs-immobilized ACNPs was 57.58% and 63.64%, respectively (for E. coli); 61.25%, and 93.49%, respectively (for S. aureus). In addition, when the AgNPs-immobilized ACNPs material was coated on the cotton and polyester fabrics, the antibacterial activity of the materials changed, becoming 19.23% (cotton; E. coli), 31.73% (polyester; E. coli), 13.36% (cotton; S. aureus), 21.15% (polyester; S. aureus).


2013 ◽  
Vol 14 (1-2) ◽  
pp. 49-60 ◽  
Author(s):  
Francesca Broggi ◽  
Jessica Ponti ◽  
Guido Giudetti ◽  
Fabio Franchini ◽  
Vicki Stone ◽  
...  

AbstractSilver nanoparticles (Ag NPs) are one of the most common nanomaterials present in nanotechnology-based products. Here, the physical chemical properties of Ag NPs suspensions of 44 nm, 84 nm and 100 nm sizes synthesized in our laboratory were characterized. The NM-300 material (average size of 17 nm), supplied by the Joint Research Centre Nanomaterials Repository was also included in the present study. The Ag NPs potential cytotoxicity was tested on the Balb3T3 cell line by the Colony Forming Efficiency assay, while their potential morphological neoplastic transformation and genotoxicity were tested by the Cell Transformation Assay and the micronucleus test, respectively. After 24 h of exposure, NM-300 showed cytotoxicity with an IC50 of 8 µM (corresponding to 0.88 µg/mL) while for the other nanomaterials tested, values of IC50 were higher than 10 µM (1.10 µg/mL). After 72 h of exposure, Ag NPs showed size-dependent cytotoxic effect with IC50 values of 1.5 µM (1.16 µg/mL) for NM-300, 1.7 µM (1.19 µg/mL) for Ag 44 nm, 1.9 µM (0.21 µg/mL) for Ag 84 nm and 3.2 µM (0.35 µg/mL) for Ag 100 nm. None of the Ag NPs tested was able to induce either morphological neoplastic transformation or micronuclei formation.


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