Antibacterial activity of green synthesized ZnO nano-flower using pineapple peel extract

Plant-based nanoparticles provide significant advantages over conventional physico-chemical techniques in medicine and biology. This paper reports the green route to synthesise ZnO particles using pineapple peel extract at various zinc precursor concentrations and evaluate their antibacterial activity. Morphological, structural, and optical properties of ZnO were characterised using SEM, XRD, FTIR, and UV–vis. The antibacterial potential of ZnO particles was evaluated against two clinical strains of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) using the paper disc diffusion method. SEM images exhibit flower-like ZnO with diameters in the range of 331–538 nm. The hexagonal wurtzite crystal phase of ZnO has been confirmed by XRD analysis with a crystal size of 14–17 nm. The FTIR spectrum has also validated the Zn-O bonding and the presence of additional functional groups in the samples. Antibacterial activity of the nanoflower ZnO towards E. coli and S. aureus displays inhibitory zone widths of 17.23 ± 3.03 mm and 30.14 ± 1.86 mm, respectively. These findings reveal that nanoflower ZnO produced using the pineapple peel extract exhibited a large bacterial inhibition zone, indicating that it is potentially used as food packaging or antibiotics.