Fabrication of polypyrrole–glucose oxidase biosensor based on multilayered interdigitated ultramicroelectrode array with containing trenches

A miniature glucose biosensor has been developed based on electropolymerization of polypyrrole–glucose oxidase on a multilayered gold interdigitated ultramicroelectrode array with containing trenches. The basal band ultramicroelectrode with a functional width of 362 nm is fabricated using multilayered materials and conventional photolithographic techniques. The electrode surface is inside the containing trenches, the depth of which is larger than 1.5 μm. High quality electrodes with uniform geometries are characterized by microscopy and electrochemical techniques. The corrosion resistance is investigated on exposure to the normal saline, which indicates that the electrodes are adequate for acute experiments lasting a few hours. Fabricated by electropolymerization, the glucose oxidase/polypyrrole (GOx/PPy) biosensors can be used for detecting glucose concentration in the linear range of 0–10 mmol/L, with a sensitivity of 13.4 nA/(mmol L) and a correlation coefficient of 0.998, respectively.