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

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 (C16EO8) 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 mu A/mm(2), and 2.8 mu A/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. (C) 2007 Elsevier B.V. All fights reserved.