Keywords:Antibacterial, Nanoparticles, Biosynthesis, Nanotechnology, electrochemical

ABSTRACT

The rapid biological synthesis of silver nanoparticles using Azadirachta indica leaves extract provides environmental friendly, simple and efficient route for synthesis of benign nanoparticles. The synthesized nanoparticles were of spherical and sheet shaped and the estimated sizes were 160-180 nm. The size were bigger as the nanoparticles were surrounded by a thin layer of proteins and metabolites such as terpenoids having functional groups of amines, alcohols, ketones, aldehydes, etc., which were found from the characterization using UV-vis spectrophotometer, SEM, DLS, Zeta Analyzer, XRD, and FTIR techniques. All these techniques it was proved that the concentration of plant extract to metal ion ratio plays an important role in the shape determination of the nanoparticles. The plant extract and those mediated silver nanoparticles were immediately tested for respective antimicrobial activities towards both gram positive (S. aureus) and gram negative (E. coli) bacterial strains showing the zones of inhibition. Based on the zone of inhibition produced, synthesized silver nanoparticles prove to exhibit good antibacterial activity against E. coli and S. aureus. On the other hand, control and plant extract alone did not exhibit any antibacterial activity. Although, it is to be presumed that the leaves extract of the plant used possess the antibacterial activities and must be reflected through greater inhibition zone but it alone shows very low activity due to its medium of extraction as well as lower concentration during experimentation.