Biosynthesis, characterisation, free radical scavenging activity and anti-bacterial effect of plant-mediated zinc oxide nanoparticles using Pithecellobium dulce and Lagenaria siceraria Leaf Extract

The study involved synthesis of Zinc Oxide nanoparticles using biological and chemical reducing agents. The aim was to compare the yield, nature and antimicrobial activity of nanoparticles. Nanoparticles synthesized by the two methods were characterized by FTIR Spectroscopy, Scanning Electron Microscopy (SEM), Energy Dispersive Xray (EDAX), Transmission Electron Microscope (TEM) and X-ray diffraction (XRD). In biological method, Pithecellobium dulce and Lagenaria siceraria leaf extract; and in chemical method, sodium hydroxide was used as reducing agents. Antibacterial study was carried out on gram-positive and gram negative bacterial strains by disc diffusion method. The biologically synthesized ZnO Nanoparticles showed better antimicrobial activities with respect to the activities of synthetic drugs than chemical method. Antioxidant potential of synthesized nanoparticles was assessed through 2,2–diphenyl-1-picrylhydrazyl (DPPH) method.