Development of a nanoscale heterostructured glucose sensor using modified microfabrication processes

Abstract

We discuss the development of a novel amperometric sensor to detect glucose concentrations in solution. Inorganic, vertically aligned nanowire arrays were employed as the sensing electrode in place of planar electrodes to utilize the unique properties of nanostructures, resulting in enhanced sensing signal from a smaller area. Heterostructured gold/platinum nanowires were used so that the dual functions of the nanoelectrodes for covalent immobilization of glucose oxidase and enhanced oxidation of hydrogen peroxide can be achieved using modified microfabrication methods. Two different enzyme immobilization methods—using self-assembled monolayers of alkanethiols and a porous conducting polypyrrole matrix—were investigated as methods for functionalizing the electrodes. Glucose sensing results were compared for planar and nanowire electrodes and the heterostructured nanowire electrodes. The results indicate that the unique structure of the sensing electrode delivers superior sensing performance from a smaller geometric area of electrodes, thus enabling further miniaturization of the sensor.