Green synthesis of silver nanoparticles using aqueous root extract of Berberis asiatica and evaluation of their antibacterial activity

Abstract

In this study, an eco-friendly method was applied for the synthesis of silver nanoparticles (Ag NPs) using an aqueous extract of Berberis asiatica. The water-soluble plant metabolites reduced silver ions into Ag NPs within 4 h at room temperature. The UV-visible absorption spectrum of the biologically reduced reaction mixture showed that a characteristic surface plasmon resonance (SPR) peak. X-ray diffraction (XRD) analysis confirmed the crystalline nature with the face-centered cubic structure of Ag NPs. Transmission electron microscope (TEM) analysis revealed the formation of Ag NPs in a spherical shape and the average size of Ag NPs around 9.8 nm, which is in agreement with the average crystallite size (14 nm) calculated from XRD analysis. The existence of Ag2O with Ag NPs and the presence of silver in Ag NPs is 27.63 % by weight, as confirmed by energy-dispersive X-ray spectroscopy (EDX). Moreover, Ag NPs prepared in this manner showed good antibacterial activity.