Green synthesis of gold nanoaprticles using black tea extract and their effect on the morphology and their antibacterial activity

Herbal extract stabilized green synthesis of nanoparticles is an alternative reducing agent for chemical synthesis. In this manuscript, green synthesis of gold nanoparticles (AuNPs) has been performed using aqueous extract of black tea. The effect of tea extract concentration on the morphology of the particles was studied. Formation, functional groups, crystalline phase, and morphology changes of the nanoparticles were characterized by UV-Vis spectrophotometer, Fourier transforms spectrometer, an X-ray diffraction pattern (XRD), scanning electron microscope (SEM), energy dispersive diffraction (EDS), and transmission electron microscopy (TEM) coupled with selected area diffraction. Antibacterial activity AuNPs were studied against bacteria. It was found that as the concentration of the tea extract increased, the shape of the particles changed and finally became spherical at high concentrations. The results of this research reveal the antibacterial activity of AuNPs.