Evaluation of Antibacterial Efficacy of Biogenic Zinc Oxide Nanoparticles on Cotton Fabrics

Growing need of potent antibacterial agents has renewed a keen interest in the development of nanomaterials with antibacterial properties. The current work demonstrated the biosynthesis of zinc oxide nanoparticles (ZnO NPs) using aqueous leaf extract of Cardiospermum halicacabum and its bactericidal activity. The resultant biogenic metal oxide nanoparticles were analyzed by various characterization techniques. UV–vis spectrum of ZnO NPs showed characteristic band at 386 nm with band gap energy 3.21 eV. SEM and TEM analysis revealed spherical and rod shaped ZnO NPs within size range 30-80 nm for spherical, 100 nm long with 5 nm width for rod shaped and the elemental composition was studied by EDX analysis. The crystalline nature of biogenic ZnO NPs was confirmed by XRD. FTIR explained about the bioactive molecules present in the leaf extract, responsible for synthesis and stabilization of metal oxide nanoparticles. Finally, antibacterial assay was carried out to evaluate the antimicrobial property of ZnO nanoparticles coated on cotton fabrics against clinical isolates, Escherichia coli (Gramnegative), Staphylococcus aureus (Gram-positive) and the bacterial survival rates treated with NPs were evaluated using live/dead fluorescence assay. The zone of inhibition showed that ZnO NPs has significant antibacterial activities against Gramnegative bacteria than the Gram-positive strain with high selectivity. This study suggests that bacteriostatic ZnO NPs might be approached to the novel therapeutic direction by development of new antimicrobial agents in clinical practice.