SnO<inf>2</inf>:Au/Carbon Quantum Dots Nanocomposites: Synthesis, Characterization, and Antibacterial Activity

Abstract

Carbon quantum dots-based nanostructures have been found more attention in recent years. In this study, Au-doped tin oxide/carbon quantum dots (Au:SnO2/carbon quantum dots) nanocomposites was prepared via simple and friendly to the environment route. The obtained results from X-ray diffraction (XRD) analysis, Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) analysis, photoluminescence spectroscopy (PL), and Ultra violet-Visible (UV-Vis) spectroscopy showed the formation of the pure and regular shape of Au:SnO2/ carbon quantum dots. Then, prepared Au:SnO2/ carbon quantum dots was utilized for the testing of antibacterial activity using Aspergillus niger,, Bacillus subtilis, Candida albicans, Escherichia coli, Klebsiella pneumonia, pseudomonas aeruginosa, Salmonella paratyphi-A serotype, Shigella dysenteriae, Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pyogenes. The modified sample showed significant improvement against tested bacteria. The best antibacterial activity was observed in Au:SnO2/ carbon quantum dots against pseudomonas aeruginosa with MIC values of 62.5 μg/ml. The obtained results demonstrate Au:SnO2/ carbon quantum dots nanocomposites are highly suitable as an antibacterial agent against both Gram-negative and Gram-positive bacteria.