High-Sensitivity Charge-Transfer-Type pH Sensor With Quasi-Signal Removal Structure

Charge-transfer-type pH sensors can be used to improve pH sensitivity with enhanced signal-to-noise ratio by applying the charge-accumulation technique. Theoretically, the pH sensitivity improves directly with the accumulated count. However, in a conventional sensor structure, a quasi-signal resulting from low charge transfer efficiency limits the accumulated count. In this paper, an effective solution to the problem of the quasi-signal and the novel sensor structure are investigated.