A novel photoelectrochemical glucose sensor based on graphene-CdS nanocomposites decorated with CoOx nanosheets

Abstract

In this work, visible light driven enzyme-free glucose PEC sensor was developed by electrochemically deposited CoOx nanosheets on graphene-CdS nanocomposites modified electrode to achieve both the electrocatalytic and photoelectrocatalytic oxidation of glucose at the resultant CoOx/graphene-CdS nanocomposites modified electrode. Scanning electron microscopy, electrochemical impedance spectroscopy and cyclic voltammetry were used to characterize the morphology and electrochemical properties of the resultant CoOx/graphene-CdS nanocomposites. The CV results demonstrated that decoration of CoOx nanosheets largely enhanced the photoelectrocatalytic activity of graphene-CdS composites toward glucose oxidation in alkaline solution. The glucose detection sensitivity under visible light irradiation is dramatically improved compared to dark condition. Good performance was obtained for the CoOx/graphene-CdS nanocomposites based glucose sensor. The feasibility of the present method was confirmed by good recovery results for glucose detection in human urine samples.