The preparation of Au decorated on ZnO nanorods by comparative DCMS/HIPIMS techniques for antibacterial activity

Abstract

Background: The mortality rate of antimicrobial-resistant infections has increased dramatically worldwide due to the increased use of antibiotics. The rise of antibiotic-resistant bacteria has highlighted the need to develop novel materials with antimicrobial properties, and nanotechnology offers promising prospects for the development of new therapeutic approaches. Currently, hybrid nanomaterials are interesting alternatives that enhance the physical and antibacterial properties of nanomaterials with a large surface area, making them efficient and biocompatible. Objectives: This study evaluated the antibacterial activity of Au nanoparticle-decorated ZnO Nanorods (NRs) with different characteristics of Au nanoparticles (Au NPs) on the ZnO surface. Materials and methods: ZnO NRs were grown on a silicon wafer using the hydrothermal method, and Au NPs were decorated on the ZnO NRs surface by DC magnetron sputtering and high-power impulse magnetron sputtering (HiPIMS) techniques for comparison. The physical morphologies and crystallinity of the ZnO NRs and Au-nanoparticle-decorated ZnO NRs were investigated by field-emission electron microscopy (FE-SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). Results: FE-SEM results indicated changes in the physical morphologies of the Au NPs on the ZnO NRs. The antibacterial efficacy of the ZnO NRs and Au-decorated ZnO NRs against Escherichia coli and Staphylococcus aureus was evaluated under UV light irradiation with bacterial concentrations ranging from 100 to 108 CFU/mL to assess their inhibitory effects using the plate count technique. Conclusion: The results demonstrated that the proposed Au-ZnO NRs exhibited a significant inhibitory effect on the growth of Escherichia coli indicating the potential of Au NPs decorated ZnO NRs as a novel antimicrobial material. Importantly, the results highlight the influence of bacterial concentration on the effectiveness of Au-ZnO NRs, offering insights for future applications in combating antibiotic-resistant bacteria. © 2025, Faculty of Associated Medical Sciences, Chiang Mai University. All rights reserved.