Synthesis of Graphene Quantum Dot Zinc Oxide Nanocomposites: Assessment of their Antioxidant and Antimicrobial Activity

Abstract

Graphene quantum dots zinc oxide (GQDs/ZnO) nanocomposites were prepared using simple, non-toxic, economical synthesis routes. The synthesized structures were characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), Scanning electron microscope (SEM), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Malvern Zeta Sizer. To determine the reducing potential of the nanostructures obtained in this study, the reducing power activity test, DPPH, and hydrogen peroxide scavenging activity tests were carried out to determine their antioxidant properties. Moreover, the xanthine oxidase inhibitory activity of GQDs/ZnO was investigated. The results showed that GQDs/ZnO nanocomposites have strong xanthine oxidase inhibitor activity. In this study, the antimicrobial activity of GQDs/ZnO nanocomposite was also investigated against Gram(+), Gram(-), and fungal strains. GQDs/ZnO nanocomposites showed different antimicrobial activity depending on these bacterial and fungal strains.