Green synthesis and antibacterial activity of zinc oxide nanoparticles using Croton macrostachyus Hochst. ex Delile extracts

Abstract

The green synthesis of zinc oxide nanoparticles (ZnO-NPs) using plant extracts is an eco-friendly and economical process compared with existing methods. The present investigation utilized the leaf and seed extracts of Croton macrostachyus Hochst. ex Delile to biosynthesize ZnO-NPs using a green technique with zinc acetate as the precursor at 80 °C for 60 minutes. XRD analysis proved the hexagonal structure of the Wurtzite ZnO-NPs, with average crystallite dimensions of approximately 40 nm. The estimated band gaps using UV-Visible spectroscopy were in the range of 3.17–3.19 eV, and FTIR, SEM, XPS, and EDS studies proved the functional groups and element contents of ZnO-NPs, in which trace levels of Ca and Mg were present in the extracts. The ZnO-NPs derived from the green synthesis method displayed high antibacterial efficacy against Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa and Klebsiella pneumoniae, which surpassed the antibacterial efficacy of the crude extracts. The green synthesis of ZnO NPs using Croton macrostachyus extracts thus presents promising results in relation to their possible antibacterial applications in the biomedical field and green nanotechnology.