Fabrication of SnO_2 decorated graphene composite material and its application in electrochemical detection of caffeic acid in red wine

摘要

Metal oxide/graphene composite has become a promising electrode material to improve the performance of electrochemical sensor. Here SnO2 decorated graphene (SnO2-RGO) composite was facilely fabricated by a hydrothermal reduction of graphene oxide with SnCl2, and applied as active electrode material into constructing electrochemical sensor for caffeic acid (CA). The SnO2-RGO composite was characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The electrochemical sensor (SnO2-RGO/GCE) obtained from SnO2-RGO coating of glass carbon electrode showed excellent electrocatalytic performance for the redox reaction of CA. A linear range of 0.15-25 mu M and a detection limit of 80 nM (S/N = 3) were achieved in 0.1 M phosphate buffer (pH 7.0). The present electrochemical sensor also showed high selectivity for CA, excellent reproducibility and stability. Eventually, the sensor SnO2-RGO/GCE was successfully applied for CA detection in commercial red wine samples with satisfactory recovery results.