Effects of Azadirachta Indica Leaf Extract, Capping Agents, on the Synthesis of Pure and Cu Doped ZnO-Nanoparticles: A Green Approach and Microbial Activity

Abstract

The current studies presented the green synthesis of zinc oxide and copper doped ZnO nanoparticles (NPs) using different ratios of Neem leaf extract and its antibacterial application on drug-resistant bacteria. The synthesized NPs were characterized using: X-ray diffractions (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscope (SEM), UV-visible spectroscopy and a simultaneous DTA-TGA thermal analyzer. All the synthesized materials were stable above 400°C. The powder diffraction studies indicated the formation of phase pure materials with wurtzite structure for pure ZnO and 0.5%, 1%, 1.5% Cu doped ZnO with the crystallite size in the range of 16.07-23.74 nm. SEM analysis revealed the formation of spherical shaped NPs with large grain size for 10% (v/v) ratio of aqueous leave extract. The aqueous extract of neem act as capping agent and prevent the NPs from agglomeration. The spectral studies confirmed the formation of NPs with the absorbance peak that is different from the micro-size ZnO. The antibacterial activities of the synthesized materials ZnO (1:1) against Staphylococcus aureus and uncalcined ZnO (7:3) and (Zn 0.985 Cu 0.015 O) against Bacillus subtilis were enhanced when referenced to the standard gentamicin.