Comparison between Different Configurations of Reference Electrodes for an Extended-Gate Field-Effect Transistor pH Sensor.

This study investigates the performance and stability of extended-gate field-effect transistor (EGFET) pH sensors with three different reference electrode configurations: conventional external Ag/AgCl, external gold (Au), and integrated Au electrodes. The goal is to identify an optimal reference electrode configuration for enhancing the portability and manufacturability of EGFET pH sensors, which are crucial in medical, agricultural, and environmental applications. Results showed that the integrated Au electrode exhibits superior stability and comparable sensitivity to those of Ag/AgCl and external Au electrodes.