Green synthesis and characterization of silver nanoparticles using leaves extracts of neem (<i>Azadirachta indica</i>) and bitter leaf (<i>Vernonia amygdalina</i>)

Abstract

Silver nanoparticles (AgNPs) were synthesized using Azadirachta indica and Vernonia amygdalina leaves extracts. Current nanotechnology research uses a lot of chemicals which are quite often toxic and flammable. In this research article, a simple and eco-friendly synthetic method for silver nanoparticles preparation was reported using the leaves extracts of Azadirachta indica (commonly called neem) and Vernonia amygdalina (commonly called bitter leaf) as reducing agents. The synthesis of AgNPs was monitored and confirmed with the use of UV-Visible spectrophotometer, Fourier Transform Infrared (FTIR) spectroscopy and Powder X-ray Diffraction (PXRD). The reduction process of Ag⁺ to Ag⁰ was observed by the change of color from yellow to brown for both leaves. The UV-Vis Spectra of AgNPs in aqueous solution showed absorbance peaks around 455 nm for Azadirachta indica and 460 nm for Vernonia amygdalina due to silver surface plasmon resonance. Crystallinity of the AgNPs was confirmed with PXRD. In addition, FTIR spectra showed that the AgNPs were capped with phytochemicals from the leaves extracts.

Keywords: AgNPs, UV-Vis, FTIR, Azadirachta indica, Vernonia amygdalina