Modulation of Biofilm with synthesized silver nanoparticles from Azadirachta indica

Study was performed for the biosynthesis of silver nanoparticle using Azadirachta indica mediated leaf extract and silver nitrate solution. After exposing the silver ions to the aqueous neem leaf extract, the rapid reduction of silver ions led to the construction of Ag-NPs in solution. The synthesized Ag-NPs were characterized using UV–Vis spectroscopy, FT-IR Spectroscopy, Scanning electron Microscopy and Energy Dispersive X-ray Spectroscopy (EDX). FT-IR result showed the biomolecules responsible for the bio-reduction of silver ion to Ag-NPs. SEM analysis showed the formation of the spherically agglomerated synthesized silver nanoparticles with size range from 31.84 ​nm to 47.85 ​nm. EDX profile showed elemental composition and the homogeneity of the synthesized silver nanoparticles and strong signal of the Ag-NPs was obtained in combination with weak signal of Carbon and Oxygen. The antibacterial activities of the synthesized Ag-NPs were evaluated against Gram Positive Staphylococcus aureus (S. aureus) and model Gram(−) Escherichia coli (E. coli) bacteria. This nanoparticle was found to be effective against the tested organisms from the zone of inhibition (ZOI) observed after 24 ​h of incubation. The Zone of Inhibition was found to be 13 ​mm and 10 ​mm against E. Coli and S. aureus respectively and the biofilm evaluated has shown a significant impact towards nanoparticle concentration.