Nanofabrication of Mesoporous Pt Electrode on Micro Pillars for CMOS Integrated micro-LOC Applications

In this paper, a newly proposed non-enzymatic Pt electrode, mesoporous Pt on micro pillars Pt electrode, is designed, fabricated, and characterized on silicon substrate by using bulk micromachining and nano technologies. The fabricated micro/nano Pt electrode has cylindrical hexangular arrayed nano Pt pores with a diameter of 3.2 nm which is formed on top of the micro pillars Pt electrode with approximately 6 mum in diameter, 6 mum in space, and 50 mum in height. The measured current responses of the fabricated plane Pt, mesoporous Pt, and mesoporous Pt on the micro pillar Pt electrodes are approximately 9.9 nA/mm², 6.72 muA/mm², and 7.67 muA/mm² in 10mM glucose solution with 0.1M phosphate buffered saline (PBS) solution, respectively. On the other hand, the measured current responses of the fabricated plane Pt, mesoporous Pt, and mesoporous Pt on the micro pillar Pt electrodes are approximately 0.15 muA/mm², 0.56 muA/mm², and 0.74 muA/mm² in 0.1 mM ascorbic acid (AA) solution with 0.1 M phosphate buffered saline (PBS) solution, respectively. This experimental results show that the proposed micro/nano Pt electrode is highly sensitive and promising for CMOS integrated and electrochemical analysis based non-enzymatic micro-LOC applications. Since the proposed micro/nano Pt electrode can also be simultaneously fabricated with the micro-fluidic mixer with the micro pillar structure, the LOCs (laboratory-on-a-chip) can be much smaller, cheaper, and easier to be fabricated.