BIOGENIC SYNTHESIS OF SILVER NANOPARTICLES USING NEEM LEAF EXTRACT AS REDUCING AGENT AND HYDROLYZED COLLAGEN AS STABILIZING AGENT
Silver nanoparticles (AgNPs) has been widely used as antimicrobial agent toward many bacterial strains and microorganisms. Biogenic method of silver nanoparticles synthesis is proven to be a safer alternative in compare to physical and chemical method. In this study, microwave-assisted green synthesis of silver nanoparticles (AgNPs) using Azadirachta indica (neem) leaf extract as reducing agent along with fish collagen as stabilizing agent have been studied. Neem extract itself has the ability to inhibit bacteria. The reduction of silver nitrate (0.01M AgNO3) solutions using neem extract was carried in microwave oven with and without collagen as stabilizing agent. The AgNPs produced were characterized by UV-Vis spectroscopy, scanning electron microscope (SEM) and x-ray diffraction analysis (XRD). The ability of AgNPs to inhibit two types of bacteria i.e Escherichia coli (E.coli) and Staphylococcus aureus (S.aureus) was conducted. The UV-visible spectra of AgNPs showed a shift to lower absorbance peak as the present of collagen. The microstructure analysis of AgNPs using SEM reveals that the synthesized silver nanoparticles particles produced around 63.4 nm for sample without collagen whereas around 39.5 nm for the sample with collagen. The XRD analysis proved the formation of AgNPs in both technique and demonstrated the crystalline nature of the silver nanoparticles. The AgNPs produced with or without collagen are able to inhibit the growth of both bacteria while AgNPs synthesized with collagen shows better antibacterial properties. This study proved that collagen can be used as stabilizing agent to produce nano silver particles with smaller particles size and better antibacterial properties.