Room temperature phytosynthesis of silver nanoparticles using leaf extract of Momordica charantia: Optical and antimicrobial properties

Abstract

Nigeria is endowed with rich diversity of medicinal plants whose potential as "green" reducing agents are under-utilized. As the world is advocating for safe environment, plant-mediated synthesis of nanoparticles is considered as an eco-friendly and sustainable synthetic route instead of using toxic chemicals. The method is fast, easy and cheaper compared with other conventional techniques. In this study, phytochemicals present in the leaf extract of indigenous Momordica charantia served as reducing, capping/stabilizing agents. The synthesized silver na-noparticles were characterized with Uv-vis spectrophotometer, photoluminescence (PL) and energy-dispersive x-ray spectrometer (EDX). Antimicrobial activities of the synthesized nanosilver were investigated on isolated Streptococcus pyogenes, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa Candida albicans and Trichophyton rubrum. Optical measurement showed surface plasmon resonance with broad absorption peaks (400-450 nm). Significant growth inhibitions were also found at P <0.05 by means of analysis of variance SPSS tool. The leaf influenced nanosilver displayed highest activity on S. aureus, S. pyogenes and E. coli with MIC and MBC value of 12.5 mg/mL. Least activity was detected against P. aeruginosa (50 mg/mL MIC and 100 mg/mL MBC). From this work, the biogenic nature and optical properties displayed by the as-prepared nanosilver strongly suggest its applications as candidate for therapeutic drugs, diagnostic and medical imaging.