Fabrication and Characterization of a Metal Oxide Semiconductor Field Effect Transistor (MOSFET)-based Micro pH Sensor

The main purpose of this study is the fabrication of an ultra-small size, simple and inexpensive metal oxide semiconductor field effect transistor-based (MOSFET) probe type pH sensor that allows fast and precise local pH measurement. First, the surface of a Pt ultra micro-electrode was coated electrochemically with polypyrrole, a semiconductor polymer, and then the probe was integrated into the gate of a MOSFET. Using the developed system, measurements were taken in PBS at different pH values. The results showed that the developed pH microsensor is sensitive to pH change. It is predicted that the micro pH sensor will allow local pH analysis in biological samples or corrosion studies.