On the basis of a metal/insulator/metal (MIM) device using electroinactive polypyrrole (PPy) film as an insulator, an amperometric pH sensor device for a very small test solution (4 μl) was developed using the structure of Au/PPy/Au with a window hole. Electropolymerized thin PPy film formed from alkaline solution is used for the ion-selective membrane. The Au/PPy/Au device with a d.c. voltage supply from 0 to 0.2 V works well as an amperometric pH sensor, that is, the gradient of the Cottrell plot within 10 s corresponds exactly to the pH value.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Metals and Alloys
- Electrical and Electronic Engineering
- Materials Chemistry