Optimal biosynthesis and characterization of broad-spectrum antibacterial cupric oxide nanoparticles using bee glue

Abstract

This work describes a simple and effective approach for producing broad-spectrum antibacterial cupper oxide nanoparticles (CuO NPs) using bee glue. The volumetric ratio of the reactants (copper salt and aqueous propolis extract) was 40 ml to 20 ml. The pH of the reaction was 8. The optimum temperature for the reaction was 70 °C, while the fastest time for the formation of these nanoparticles was 13 minutes. Ultraviolet-visible ray absorption spectra indicated surface plasmon resonance at around 300 nm, proving the synthesis of CuO NPs. The Fourier-transform infrared spectra study confirmed the presence of the CuO nanoparticles at 533-582 cm^-1, as well as the responsible biomolecules for the capping and stability of these nanoparticles.

 X-ray powder diffraction and transmission electron microscopy determined the shape and size of the CuO NPs nanoparticles. These nanoparticles have a monoclinic shape and an average size of 31.75 nm.

The antibiotic activity assay results of CuO NPs were impressive and promising against six different strains of microbes.