Facile Fabrication of CeO/Electrochemically Reduced Graphene Oxide Nanocomposites for Vanillin Detection in Commercial Food Products.

In this paper, CeO nanoparticles were synthesized by the solvothermal method and dispersed uniformly in graphene oxide (GO) aqueous solution by ultrasonication. The homogeneous CeO-GO dispersion was coated on the surface of a glassy carbon electrode (GCE), and the CeO/electrochemically reduced graphene oxide modified electrode (CeO/ERGO/GCE) was obtained by potentiostatic reduction. The results of X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) showed that CeO nanocrystals were uniformly coated by gossamer like ERGO nanosheets. The electrochemical behavior of vanillin on the CeO/ERGO/GCE was studied by cyclic voltammetry (CV). It was found that the CeO/ERGO/GCE has high electrocatalytic activity and good electrochemical performance for vanillin oxidation. Using the second derivative linear sweep voltammetry (SDLSV), the CeO/ERGO/GCE provides a wide range of 0.04-20 µM and 20 µM-100 µM for vanillin detection, and the detection limit is estimated to be 0.01 µM after 120 s accumulation. This method has been successfully applied to the vanillin detection in some commercial foods.