Glucose sensing based on multilayered interdigitated ultramircoelectrode array

A gold submicrometer multilayered interdigitated ultramicroelectrode array (IDA) is fabricated by conventional photolithographic patterning of multilayered materials on a quartz substrate. The IDA is fabricated in a small region (1.5 mm × 2.3 mm) and consists of 50 pairs of fingers. The finger length is 1.5 mm. The functional width of the electrode is 362 nm and the electrode surface is inside the trenches. The IDA electrodes can be used as disposable ultramicroelectrodes of chemical and biologic sensors. Glucose biosensors are fabricated by electropolymerization of glucose oxidase/polypyrrole (GOD/PPy) on the IDA electrodes. The experiment results show that the glucose sensors have a fast response time of about 10 s and a linear calibration range from 2.0 to 7.0 mmol/L glucose concentration with the high sensitivity of 14.6 nA (mmol/L) ^-1 in potassium phosphate buffer solution (pH 7.0).