Electrochemical Sensing Based on Au particle@SiO2@CQDs Nanocomposites

Abstract

Abstract In this study, carbon quantum dots (CQDs) were first synthesized using a hydrothermal method, and then Au@SiO2 core-shell nanomaterials were synthesized using layer-by-layer assembly. CQDs were adsorbed on the surface of Au@SiO2 nanoparticles through self-assembly to form Au@SiO2@CQDs nanocomposite materials. Transmission electron microscopyand X-ray diffraction were used to characterize the size, shape, element composition, and structure of nanocomposites; ultraviolet-visible absorption spectroscopy and fluorescence spectroscopy were used to analyze the optical properties of nanocomposites. The results show that Au@SiO2@CQDs nanomaterials have a core-shell structure with good morphology and exhibit excellent luminescence characteristics. The electrochemical performance of nanocomposites was characterized using electrochemical means, and a hydrogen peroxide sensor was constructed for the sensitive detection of hydrogen peroxide, thus realizing the rapid and sensitive detection of hydrogen peroxide at levels as low as 0.2 mM.