Hybrid ZnO–graphene electrode with palladium nanoparticles on Ni foam and application to self-powered nonenzymatic glucose sensing

Abstract

A self-powered nonenzymatic glucose sensor electrode boasts the advantages of both a glucose sensor and fuel cell. Herein, an electrode composed of ZnO–graphene hybrid materials on nickel foam (NF) is prepared by electrodeposition of Pd NPs. The electrode is characterized systematically and the dependence of electrocatalytic oxidation of glucose on the concentrations of KOH and glucose, temperature, and potential limit in the anodic direction is investigated. The Pd/NF-ZnO–G electrode shows high catalytic activity, sensitivity, stability, and selectivity in glucose detection, as exemplified by an electrocatalytic glucose oxidation current of 222.2 mA cm⁻² under alkaline conditions, high linearity in the glucose concentration range from 5 μM to 6 mM (R² = 0.98), and high sensitivity of 129.44 μA mM⁻¹⁻¹ cm⁻². The Pd/NF-ZnO–G electrode which exhibits superior electrocatalytic activity under alkaline conditions has large potential in nonenzymatic glucose sensing and direct glucose fuel cells and is suitable for miniaturized self-powered nonenzymatic glucose sensing.