Green synthesis of silver nanoparticles with antibacterial activities using aqueous Eriobotrya japonica leaf extract

Bo Rao and Ren-Cheng Tang

Abstract

An eco-friendly approach for the preparation of silver nanoparticles (AgNPs) from silver nitrate solution using aqueous Eriobotrya japonicaleaf extract was investigated. The reduction of silver ions in solution was monitored using UV–visible absorption spectroscopy, and the surface plasmon resonance of AgNPs at 435 nm was observed. The proper condition to biosynthesize AgNPs using E. japonica leaf extract was optimized by UV–visible absorption spectroscopy and dynamic light scattering measurement (DLS). The biosynthesised nanoparticles were characterised using transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX), DLS, x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). XRD and EDX analyses confirmed the crystalline character of AgNPs and the presence of elemental silver. The prepared AgNPs were spherical in shape, and their average particle size determined by TEM was about 20 nm. Furthermore the AgNPs were found to exhibit effective antibacterial activities against Escherichia coliand Staphylococcus aureus