Demonstration of Detecting Small pH Changes Using High-Sensitivity Amorphous InGaZnO4 Thin-Film Transistor pH Sensor System

In this brief, we discuss our top-gate-effect- basedhigh-sensitivityamorphous InGaZnO4 thin-film transistor (a-InGaZnO TFT) pH sensor system. The pH sen-sor system consists of an a-InGaZnO TFT pH sensor and a driving circuit that was designed to bring out the high-sensitivity performance of the sensor. We present a primary demonstration for the a-InGaZnO TFT pH sensor system that has the potential for accurately detecting stepwise pH changes as small as 0.02.