Photoelectrochemical response of non-enzymatic glucose biosensing for graphene, carbon nanotubes and BiVO4 nanocomposites

Abstract

Diabetes mellitus is a worldwide disease which affects the vital organs of human body. The approach executed in this project is to fabricate the nanocomposites of BiVO4 by incorporating reduced graphene oxide (RGO) and carbon nanotubes (CNT) for photoelectrochemical non-enzymatic glucose detection. These different composites were prepared using electrochemical deposition method. X-ray Diffraction (XRD) and scanning electron microscope (SEM) analysis confirmed the structural details and surface morphology of these nanostructures, graphene sheet, BiVO4 nanoparticles and of carbon nanotubes. UV–Vis analysis revealed the increasing trend in absorption of light and absorption edge, for BiVO4, CNT/BiVO4, RGO/BiVO4 and CNT/RGO/BiVO4 electrodes, respectively. The photoelectrochemical response was measured through Linear Sweep voltammetry and increase in current density was observed from pure BiVO4nanoparticles to CNT/BiVO4 to RGO/BiVO4 and to CNT/RGO/BiVO4, due to incorporation of graphene and carbon nanotubes. The increasing glucose oxidation current was measured through cyclic voltammetry. It was observed that glucose oxidation peak was maximum for CNT/RGO/BiVO4 electrode, as the incorporation of extremely conductive CNTs specifies several routes for the transportation of electrons and act as an impressive conductive binders to restrict the agglomeration of graphene nanosheets, thus enhancing the rate of electrons exchange. This study shows that CNT/RGO/BiVO4 electrode is the best photoelectrochemical electrode for non-enzymatic glucose detection for providing maximum sensitivity of 501.5 mA cm−2 mM−1 and good stability with negligible current response from interference species.