Abstract

This research focused on isolation of Silver Nano Particles (AgNPs) using leaf filtrate of Ocimum sanctum and evaluation of their antibacterial action against Bacillus aureus, Staphylococcus aureus and Escherichia coli. It is known that plant extracts act as reducing agents, stabilizers and as capping agents. The O. sanctum plant was specifically selected due to its medicinal properties and abundant availability. The change in color of leaf extract was imminent when the silver nitrate was added to the basil leaf filtrates, indicating the formation of AgNPs. The UV-visible spectroscopy and SEM analysis confirmed the formation of AgNPs. Silver ions and nanoparticles are severely toxic to microorganisms; hence they are used predominantly as antimicrobial agents. The silver nanoparticles that were synthesized from O. sanctum leaf extract have exhibited antibacterial activity against Klebsiella, B. aureus, S. aureus and E. coli and the activity varied significantly with the different concentrations of silver nitrate used. The nano particles thus developed have been confirmed by UV along with SEM reports. AgNPs sizes varied from 53.3 to 121 nm. It has been observed that most of the plant extracts yielded silver nano particles of size less than 100 nm. However, the present experimental work yielded particle size of about 121 nm from O. sanctum leaf extract.

Key words: Silver nano particles (AgNPs), Ocimum sanctum, antibacterial activity.