標題: | A precise pH microsensor using RF-sputtering IrO2 and Ta2O5 films on Pt-electrode |
作者: | Kuo, Li-Min Chou, Yi-Chia Chen, Kuan-Neng Lu, Chien-Chia Chao, Shuchi 電子物理學系 電子工程學系及電子研究所 Department of Electrophysics Department of Electronics Engineering and Institute of Electronics |
關鍵字: | IrO2;Ta2O5;pH sensor;Proton-electron double injection;Solid-state sensor |
公開日期: | 1-三月-2014 |
摘要: | In this study, an easily implemented surface modification scheme is reported employing Ta2O5 membrane which covers IrO2 electrode in response to H+ and eliminating redox species interference. Evidence shows that H+ can pass through Ta2O5 films and react with IrO2/Pt electrodes due to proton-electron double injection. A Ta2O5 membrane, an ionic conductor with an insulating property, blocks the transport of electrons generated from oxygen perturbation in the solution. The conduction of both electrons and protons preserve the current continuity across the interface. Owing to proton-electron double injection, IrO2 will be reduced to Ir(OH)(3) during pH detection. The [IrO2]/[Ir(OH)(3)] will remain constant and therefore the Nernstian electrode potential performs stably as a function of pH (-59.447 to -59.504 mV/pH, 2< pH <13). In addition, the proposed pH microsensor displayed high ion selectivity with respect to K+, Na+, and Li+, with log K-H,K-M values (similar to-12.4) and has a working lifetime over one week. (C) 2013 Elsevier B.V. All rights reserved. |
URI: | http://dx.doi.org/10.1016/j.snb.2013.11.109 http://hdl.handle.net/11536/23572 |
ISSN: | 0925-4005 |
DOI: | 10.1016/j.snb.2013.11.109 |
期刊: | SENSORS AND ACTUATORS B-CHEMICAL |
Volume: | 193 |
Issue: | |
起始頁: | 687 |
結束頁: | 691 |
顯示於類別: | 期刊論文 |