Green synthesis, characterization and preliminary antimicrobial study of silver nanoparticles from Parquetina nigrescens (Afzel)

Abstract

The recent geometrical increase in the applications of nanosized materials in almost all areas of human endeavours has continued to draw keen interest of scientists to the investigations on nanoscience and nanotechnology. To meet the increasing demands for commercial nanoparticles, green synthesis method, which is simple and eco-friendly is the widely preferred option of production of nanoparticles at laboratory and industrial scales. This study reports the synthesis of silver nanoparticles using Parquetina nigrescens (Afzel) extract and its characterization using ultraviolet visible spectroscopy, Fourier Transform Infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Four (4ml) of the aqueous bark extract was mixed with 36ml of silver nitrate and shaken continuously for 1 hour until a deep brown colour was observed. The electron microscopic study carried out on the synthesized AgNPs shows that the synthesised AgNPs were spherical, with sizes ranging from 0.092 to 0.375 μm as shown by SEM analysis. The UV-visible spectroscopy of the synthesized Parquetina nigrescens silver nanoparticles shows maximum absorbance at 436.92nm. The FTIR spectrum shows strong peaks at 3334.23, 2872.60, 2095.63 and 1625.94 cm-1. The synthesised AgNPs show inhibition against the growth of Pseudomonas, Aspergillus flavus (76%), Aspergillus niger (81.17%) and Aspergillus fumigatus (44.87%) fungi. This study has shown that the green synthesised AgNPs from parquetina nigrescens have a strong antimicrobial activity and potential biomedical applications.