Synthesis and characterization of zinc oxide and Mg-doped ZnO nanoparticles using M. stenopetala leaf extract and evaluation of their antimicrobial activities

Abstract

Nowadays, much attention is paid to metal and metal oxide nanoparticles, which exhibit chemical and physical properties owing to their extremely small dimensions and high specific surface area. The main objective of the study was the synthesis and characterization of ZnO and Mg-doped zinc oxide nanoparticles using M. stenopetala leaf extract and the evaluation of their antimicrobial activities. The study was conducted using precipitation method of synthesis of nanomaterial. Characterization of ZnO and Mg-doped ZnO nanoparticles were studied by UV-VIS Spectroscopy, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscope, Cyclic Voltammetry, and X-Ray Diffraction. UV-VIS Spectroscopy analysis indicated the absorption spectrum of ZnO NPs. Fourier Transform Infrared Spectroscopy analysis indicated the functional groups present in the synthesized ZnONPs. The vibrational stretching around 550 cm-1 (Zn-O) supports the formation of ZnO nanoparticles. The particle size and of the synthesized ZnONPs were studied by X-Ray diffraction (XRD) pattern and which confirmed the formation of nanoparticles. The synthesized nanoparticles have a hexagonal wurtzite structure with an average grain size of 27.72 nm and which was confirmed by X-ray diffraction analysis. The morphology of zinc oxide and 3% magnesium-doped ZnO nanoparticles was studied using a scanning electron microscope. The SEM study indicated that the shape and morphology of ZnO and 3% Mg-doped ZnO NPs changes with increasing Mg concentration. The cyclic voltammetry analysis confirmed that ZnO nanoparticles exhibited excellent oxidation-reduction behavior and confirmed that the plant extract were used as efficient reducing agent during the synthesis of the nanomaterials. For antimicrobial activities gram-positive bacteria (S. aureus B. cereus,), gram-negative bacteria (E. coli, S. typhus,) and fungus (C. albicas) were used using the agar plate disc diffusion method. The study also clearly states the antimicrobial activity and proof the leaf extract, ZnO nanoparticles, and 1%, 2%, and 3% Mg-doped ZnO nanoparticles have excellent potential application in antimicrobial activity.