Antibacterial fabrics: ZnO nanoparticles infused polymer nanofiber membrane

Abstract

Bacterial infections are a leading global health crisis, ranking as the second largest cause of death worldwide. This study explores the innovative potential of using polyvinyl alcohol (PVA) nanofiber membranes infused with ZnO nanoparticles to create antibacterial clothing. ZnO, is a n-type semiconductor with a band gap of approximately 3.37 eV, is renowned for its biosafety and biocompatibility. It exists in various forms such as nanowires, nanorings, nanospheres, and nanohelices, showcasing its versatility. Additionally, ZnO nanoparticles exhibit significant antibacterial properties against a wide range of bacterial species due to their photocatalytic activity, making them a promising solution in the fight against transmission of bacterial infections. Electrospinning has been employed to fabricate PVA nanofiber membranes, with PVA emerging as the predominant polymer of choice due to its non-toxicity, biocompatibility, and superior electrospinning-ability compared to other polymers. The agar disc diffusion method was carried out to observe antibacterial activity of ZnO nanoparticles and PVA-ZnO nanofiber membranes against Escherichia coli DH-5α (E-coli) strain. A distinct inhibition, zone with an average width of approximately 0.5 cm, was clearly observable using commercially available ZnO nanoparticles. PVA-ZnO nanofiber membranes with different ZnO concentrations were fabricated starting from 0.5 wt% to 6.0 wt%, in steps of 0.5 wt%, on a gauze as a substrate, by electrospinning PVA-ZnO polymer solutions. The antibacterial activity of the PVA-ZnO nanofiber membranes started to appear when the ZnO concentration was 5.0 wt%. These membranes exhibited an average inhibition zone width of approximately 0.1 cm. Also, PVA nanofiber membrane alone did not show an inhibition zone. Surface morphology of each nanofiber was analyzed using scanning electron microscope (SEM). X-ray Fluorescence (XRF) analysis for the commercially available ZnO nanoparticles was performed to determine the chemical purity of the ZnO. Fourier Transform Infrared spectroscopy (FTIR) analysis was performed to determine the structural change due to the interaction between PVA and ZnO nanoparticles. Based on the findings, a minimum ZnO concentration of 5.0 wt% is necessary to achieve antibacterial activity against E-coli using PVA-ZnO nanofiber membranes. This concentration threshold underscores the critical role of ZnO in enhancing the membranes' effectiveness in fighting against bacterial pathogens.