Glucose oxidase immobilized macro porous silicon based conductive glucose sensor

Conductive glucose sensor using glucose oxidase immobilized macro porous silicon has been studied in this paper. Macro porous silicon layer is grown on p-type silicon substrate by electrochemical etching process. Two electrodes have been made with silver on front side of the macro porous silicon layer. Then the macro porous silicon surface has been functionalized for efficient glucose sensing by physisorption of glucose oxidase. Current–voltage characteristics have been studied at different glucose concentrations. Current value initially increases due to adsorption of glucose molecules upto 1 mM glucose concentration, after that current value decreases with increasing glucose concentration. Sensor response has been analysed with the help of different types of conduction mechanisms like hopping, Poole–Frenkel, trap-assisted and Fowler–Nordheim tunneling. Different conduction mechanisms are dominating at different applied field ranges. The sensor shows good response, high sensitivity and excellent repetitive behavior.