Honey mediated synthesis of zinc oxide nanoparticles, and evaluation of antimicrobial, antibiofilm activities against multidrug resistant clinical bacterial isolates

The present work aims to synthesize zinc oxide nanoparticles (ZnONPs) via a greener approach using honey as a bio-reductant and stabilizing agent. The prepared nanoparticles were analysed by using UV-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), crystalline nature by X-ray diffraction (XRD), field electron scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), size distribution and zeta potential by dynamic light scattering (DLS) analysis. XRD patterns demonstrate the polycrystalline wurtzite structure for ZnONPs with an average zeta potential value of- 2.61 mV. Spherical and square-shaped nanostructures were affirmed using FE-SEM and TEM micrographs. The DPPH and ABTS assays revealed that ZnONPs possess antioxidant activity with an IC50 value of 38 mu g/mL and 6.38 mu g/mL, respectively. Additionally, the antimicrobial activity of ZnONPs performed against clinical strains of Gram negative bacteria such as Klebsiella pneumoniae (K. pneumoniae), Escherichia coli (E. coli), and Gram positive bacteria Methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa (P. aeruginosa), and Staphylococcus aureus (S. aureus) was assessed along with their antibiofilm activity. The evaluation of the integrity of the bacterial cell membrane with the leakge of cellular components, including nucleic acids and proteins, into the culture medium indicated that honey synthesized ZnONPs could function as potential antimicrobial agents.