Intrinsic peroxidase-like activity and the catalytic mechanism of gold@carbon dots nanocomposites

Abstract

Well-dispersed AuNPs@CDs nanocomposites were successfully synthesized from the reduction of chloroauric acid by carbon dots (CDs) at room temperature. The as-prepared AuNPs@CDs were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS), and the results indicate AuNPs@CDs nanocomposites with a core–shell structure. The AuNPs@CDs are found to possess intrinsic peroxidase-like activity, and the catalytic activity is higher than that of AuNPs. The mechanism of peroxidase-like activity of AuNPs@CDs was investigated by fluorescence spectroscopy, electron spin resonance and cyclic voltammetry, and it is found that the mechanism could be ascribed to facilitating the electron transfer between TMB and H₂O₂.