Characterization of Stress-Tolerant Bacteria for the Biosynthesis of Silver Nanoparticles and their Applications

2021 ◽  
Vol 68 ◽  
pp. 70-80
Author(s):  
Amrisha Srivastava ◽  
Puneet Singh Chauhan ◽  
Rachana Singh

The biogenesis of silver nanoparticles by microbes has become an essential branch in the field of nanotechnology because of its safe, environment-friendly, economical, and time-saving nature. In the current research work, we have screened some stress-tolerant bacteria based on pH, temperature, salt-tolerant efficacy and further utilized them for the synthesis of silver nanoparticles. The test bacterium was isolated from the soil sample through the serial dilution method on nutrient agar media (NAM). Based on identification using morphological characteristics, biochemical analysis, and 16srRNA sequencing bacteria were identified as Bacillus sp. The extracellular biosynthesis approach was used for synthesizing silver nanoparticles by Bacillus sp. Characterization of synthesized silver nanoparticles was done by using UV-Visible Spectrophotometer and absorbance peak was recorded at 430nm. Transmission electron microscopy (TEM) study of synthesized nanoparticles showed the shape of nanoparticles was spherical and hexagonal with a size ranging from 10nm-47nm. For the extracellular biosynthesis of silver nanoparticles pH was set to 7.0 and temperature at 37°C.

Nanoscale ◽  
2011 ◽  
Vol 3 (2) ◽  
pp. 635-641 ◽  
Author(s):  
Navin Jain ◽  
Arpit Bhargava ◽  
Sonali Majumdar ◽  
J. C. Tarafdar ◽  
Jitendra Panwar

2019 ◽  
Vol 812 ◽  
pp. 66-74 ◽  
Author(s):  
Diana P. Ferreira ◽  
Sofia M. Costa ◽  
Helena P. Felgueiras ◽  
Raul Fangueiro

Multifunctional fibrous systems were developed within this research work, giving special importance to the electrical conductivity and antibacterial activity. The functionalization of several natural fibres (jute, sisal, coir, flax and cotton) with silver nanoparticles (Ag NPs) was successfully achieved using a sustainable and eco-friendly method, namely polyethylene glycol (PEG) reduction. FESEM images, GSDR and ATR-FTIR analysis show that the Ag NPs were incorporated onto the fibres surface. The resistivity values obtained by analysing the fabrics without functionalization was about 1.5x107 Ω.m while with the Ag NPs functionalization the resistivity values decreased almost 15000 times, to 1.0x 103 Ω.m. Jute fibres’ antibacterial efficiency was also studied using the fibres with incorporated nanoparticles. Jute/Ag NPs showed some activity against E. Coli and S. Aureus. Polylactic acid (PLA) was used to develop flexible biodegradable composites with the functionalized jute. The compatibilization of the jute with PLA was successful and the characterization of the final composites was performed by GSDR, ATR-FTIR and TGA.


2019 ◽  
Vol 29 (3) ◽  
Author(s):  
Mai Ngọc Tuan Anh

Silver nanoplates (SNPs) having different size were synthesized by a seed-mediated method. The seeds -silver nanoparticles with 4 – 6 nm diameters were synthesized first by reducing silver nitrate with sodium borohydride in the present of Trisodium Citrate and Hydrogen peroxide. Then these seeds were developed by continue reducing Ag\(^+\) ions with various amount of L-Ascorbic acid to form SNPs. Our analysis showed that the concentratrion of L-Ascorbic acid, a secondary reducing agent, played an important role to form SNPs. In addition, the size and in-plane dipole plasmon resonance wavelenght of silver nanoplates were increased when the concentration of added silver nitrate increased. The characterization of SNPs were studied by UV-Vis, FE-SEM, EDS and TEM methods.


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