Investigating the Antibacterial Activities of Graphene Oxide Loaded Spiky Gold Nanocomposites via Chitosan linker

Abstract

The graphene oxide (GO) loaded spiky gold (AuNS) nanocomposites were prepared by electrostatic interaction between negatively-charged GO nanosheets and positively-charged AuNS by the assistance of chitosan as linker molecules. The AuNS/GO nanocomposites exhibit a red-shift in the extinction spectra and a reduction in the zeta potential compared to those of the pristine AuNS due to the presence of oxygen-containing functional groups in GO. The bactericidal analysis demonstrates that the incorporation of GO greatly enhances the intrinsic antibacterial activities of AuNS. Besides, the AuNS with smaller size exhibit better bactericidal efficiency compared to that of AuNS with bigger size. Upon light irradiation, the AuNS/GO with the absorption peak close to the wavelength of excitation light (900 vs. 904 nm) demonstrates a noticeable improvement in the bactericidal efficiency which is attributed to the plasmon-induced photothermal effect. All these results suggest that the AuNS/GO nanocomposites can work as a promising functional material for both intrinsic and plasmon-induced antibacterial materials.