A pH-sensitive sensor with a differential mode was developed to detect surface charges accumulated on the ion-sensitive layer. The device accurately monitors the relative pH value using the modified instrumentation amplifier with the DC electrode-offset compensation. The readout voltage is digitalised with the current-starved ring oscillator. The sensor achieves the DC offset compensation of 22.5 dB and the oscillating pH sensitivity of 1.3 MHz/pH. The feasibility of the sensor is demonstrated to monitor the hydrogen ion concentration comparing the oscillation frequency at differential mode with that at single mode.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.