Biosynthesis characterization of gold and silver nanoparticles by using different medicinal plants and evaluation of its biological activities

Abstract

The Nano technology is an emerging field of science revolutionized important technologies newlinein all areas of science. The nanoparticles offer unprecedented interaction with biomolecules newlinedue to their small size, shape, and structure. In this study three medicinal plants, Justica newlinewynaadensis, Lobelia nicotianifolia, and Abrus precatorius seed extracts were used to newlinesynthesize Au and Ag nanoparticles, and their biological activities were studied. Ethyl newlineAcetate extract of the samples was used for the investigation. The synthesis of Au and Ag newlinenanoparticles was carried out by adding 10ml chloroacetic acid (AuCl4) and 1 molar Ag newlinenitrate solution (AgNO3) separately into a conical flask. The color that appeared during the newlinereaction was recorded. The reaction mixture was allowed to cool and Uv-spectral analysis newlinewas observed at 500nm to 600nm for Au, 400 nm-500 nm for Ag nanoparticles. The readings newlinewere recorded for Au in the range between 420 to 455 nm and for Ag 532nm to 560 nm. The newlinesolution was allowed to react up to 24 hours and solutions were centrifuged at 10,000 rpm for newline20 minutes pellets were used for further study. The nanoparticles were subjected to newlinecharacterization technique, XRD analysis of Au and Ag nanoparticles confirmed the newlinecrystalline structure and size of the nanoparticle was calculated using Debye-schererr newlineequation D=0.9and#955;/and#946;Cosand#952;. newlineFTIR studies confirmed the functional groups involved in capping Au and Ag newlinenanoparticles.TEM images confirmed the polydispersed agglomerated Ag and Au newlinenanoparticles with sizes ranging from 14 nm to 80 nm. SAED confirmed the fcc (Face newlinecentered cubic) structured Ag and Au nanoparticles incorporation with XRD pattern. EDX newlineanalysis confirmed the purity of the nanoparticles with no impurities. The anti-microbial newlineactivity of the Ag and Au nanoparticles was tested against gram-positive bacteria newlineMicrococcus luteus, Bacillus subtilis, and Escherichia coli, and a clear zone of inhibition was newlinerecorded. The anticancer activity (MTT assay) was evaluated against human lung cancer newline