Fabrication and characterization of nano-hole-arrayed Pt electrode on silicon for CMOS integrated non-disposable biosensor applications
Since most biosensors are based on enzymatic electrochemical analysis, they are disposable due to the use of enzymes that are living creatures. Thus, these are limited to use in in-vivo and mobile monitoring-system applications. In this paper, a nano-hole-arrayed platinum electrode is fabricated and characterized on silicon substrate, to be used as a sensing electrode without any enzymes, for developing non-disposable biosensors integrated with silicon CMOS read-out circuitry. The proposed nano-hole-arrayed Pt electrode was fabricated by using a nonionic surfactant C16EO8 and an electrodeposition technique. Electrodeposition was performed at various applied voltages and charges to find an optimized condition. The optimized nano-hole-arrayed Pt electrode was fabricated at the applied voltage of -0.12 V and charge of 65 mC. In the comparison of the optimized nano-hole-arrayed Pt electrode and the plane (non-treated) Pt electrode, the amperometric response of the nano-hole-arrayed Pt electrode is about 30 times more sensitive than that of the plane Pt electrode in glucose with PBS (phosphate buffered saline: 0.1 M, pH 7.4) solution. This result shows that the nano-hole-arrayed Pt electrode is promising for the development of non-disposable electrochemical sensors.