A Highly Miniaturized Dissolved Oxygen Sensor Using a Nanoporous Platinum Electrode Electroplated on Silicon

摘要

A highly sensitive and miniaturized dissolved oxygen (DO) sensor with a nanoporous platinum (Pt) electrode on a silicon substrate was recently developed and characterized for use in environmental monitoring and bio/medical sensor applications. The proposed DO sensor was designed with four different ayers: the electrodes (a nanoporous Pt working electrode, a plane Pt counter electrode, and a Ag/AgCl reference electrode), a poly(dimethylsiloxane) (PDMS) passivation electrolyte reservoir, a PDMS film used as a gas permeable membrane, and a PDMS chamber for storing the DO sample. The fabricated DO sensor has a compact size and a volume of 15 mm x 8 mm x 8.05 mm. The utilized nanoporous Pt working electrode of the DO sensor showed a much larger roughness factor (RI?), at 313, than the plane Pt electrode did. At various oxygen concentrations, the fabricated sensor exhibited distinctive response currents, a high oxygen sensitivity of 102.78 nA/ppm, a fast response time of less than 100 sec at -0.8 V vs. Ag/AgCl, and a good reproducibility at room temperature and pressure. We confirmed these excellent results were caused by the highly-roughened catalytic nanoporous Pt electrode.