Construction of a photovoltaic glucose sensor applying a metal-insulator-silicon structure in combination with ultra-thin polypyrrole-glucose oxidase film

An enzyme-metal-insulator-silicon (EMIS) structured chemical sensor based on photovoltage technology is constructed for potentiometric biosensing of glucose in a flow-injection analysis (FIA) system. To enhance the sensibility of the sensor to glucose, an ultra-thin (60 nm) film of polypyrrole (PPy)-glucose oxidase (GOD) is formed as the glucose-sensitive membrane through a simple electropolymerization process in the absence of supporting electrolyte. The introduction of photovoltage technology and the electroimmobilization of GOD are advantageous in improving the sensitivity, selectivity, response time, linear range, stability and lifetime of potentiometric sensor for glucose measurement. Thus the photoelectric hybrid glucose sensor has extensive potential both in rapid determination of plasma glucose and long-time continuous monitoring of glucose concentration in extracellular microenvironment.