BIOLOGICAL SYNTHESIS OF SILVER NANOPARTICLES BY USING ONION (ALLIUM CEPA) EXTRACT AND THEIR ANTIBACTERIAL ACTIVITY

The synthesis of metal and semiconductor nanoparticles is an expanding research area due to the potential applications for the development of novel technologies. Generally, nanoparticles are prepared by a variety of chemical methods which are not environmentally friendly. We have reported a fast, convenient and extracellular method for the synthesis of silver nanoparticles by reducing silver nitrate with the help of onion (Allium cepa) extract. The characterization of nanoparticles was done by using UV- Vis Spectrophotometer and Dynamic Light Scattering (DLS). The morphology of silver nanoparticles was confirmed by Transmission Electron microscopy (TEM). The antibacterial activity of these nanoparticles was studied against E. coli and Salmonella typhimurium. The bactericidal property of nanoparticles was analyzed by measuring the growth curve of bacteria and 50 mu g/ml concentration of silver nanoparticles was found to be effective antibacterial.