Using polypyrrole as the contrast pH detector to fabricate a whole solid-state pH sensing device

Author

Pan, Chung-We ; Chou, Jung-Chuan ; Kao, I-Kone ; Sun, Tai-Ping ; Hsiung, Shen-Kan

Author_Institution

Inst. of Electron. Eng., Chung Yuan Christian Univ., Chung-li, Taiwan

Volume

3

Issue

2

fYear

2003

fDate

4/1/2003 12:00:00 AM

Firstpage

164

Lastpage

170

Abstract

In this paper, we use the extended gate field effect transistor (EGFET) and the coated wire electrode (CWE) to design a differential pH-sensing device. The SnO₂/ITO glass structure is the EGFET used as the pH sensor because of its excellent pH sensitivity of about 57.10 mV/pH. The contrast pH sensor is the polypyrrole/SnO₂/ITO glass structure CWE, which has the lower pH sensitivity of about 27.81 mV/pH, and we use the third SnO₂/ITO glass structure as the reference electrode to serve the base potential of the electrolyte solution. The pH sensitivity of this differential pH-sensing device is about 30.14 mV/pH and it is linear. Hence, this device is a good pH sensor. By using this technology, the differential pH-sensing device has a lot of advantages, such as simple fabrication, solid-state electrodes, easy packaging, low cost, etc.

Keywords

chemical sensors; electric sensing devices; field effect transistors; indium compounds; pH measurement; polymer films; tin compounds; EGFET; JkJk-SnO2-InSnO; base potential; coated wire electrode; contrast pH detector; cost; differential pH-sensing device; extended gate field effect transistor; packaging; polypyrrole; polypyrrole/SnO₂/ITO glass structure; reference electrode; solid-state electrodes; solid-state pH sensing device; Costs; Detectors; Electrodes; FETs; Fabrication; Glass; Indium tin oxide; Packaging; Solid state circuits; Wire;

fLanguage

English

Journal_Title

Sensors Journal, IEEE

Publisher

ieee

ISSN

1530-437X

Type

jour

DOI

10.1109/JSEN.2002.807300

Filename

1202939