Fabrication and characterization of platinum black and mesoporous platinum electrodes for in-vivo and continuously monitoring electrochemical sensor applications

摘要

Most electrochemical biosensors are disposable due to enzymes that are living creatures. Thus, these are limited to use in in-vivo and continuously monitoring biosensor system applications. The mesoporous (pores with a size of 2-50 nm) platinum (Pt) structure formed on a rod-shaped Pt microelectrode was reported for developments glucose sensors without any enzymes. In this paper, plane Pt electrode (non-treated), Pt black electrode, and mesoporous Pt electrode are fabricated and characterized on a silicon substrate in order to check their usability as enzymeless sensing electrodes for in-vivo and continuously monitoring electrochemical biosensors integrated with silicon CMOS read-out circuitry. The Pt black electrode with rough surface was fabricated by using an electrodeposition technique with hexachloroplatinic acid hydrate (HCPA) solutions. The proposed mesoporous Pt electrode with approximately 3 nm in pore diameter was fabricated by using an electrodeposition technique with nonionic surfactant octaethylene glycol monohexadecyl ether (C_(16)EO_8) and HCPA. The measured current responses at 40 mM glucose solution of the fabricated plane Pt, Pt black, and mesoporous Pt electrodes are approximately 12.4 nA/mm~2, 2.1 μA/mm~2, and 2.8 μA/mm~2, respectively. These data indicate that the mesoporous Pt electrode is much more sensitive than the other Pt electrodes and has strong potential for enzymeless electrochemical sensor applications.