146 / 2021-04-18 09:35:27

Extended-gate Field Effect Transistors with Zinc Oxide as sensing film for pH Sensing

pH sensing,extended gate field effect transistor,ionic solution

Bioelectronics > Biomedical Devices

Ion sensitive field effect transistor (ISFET) is composed of an ion selective sensing film and a transistorand is able to convert the chemical information of ion concentration into the change of current or voltage. As the oxide of the transistor of ISFET is directly contacted with the solution,  it leads to unstable sensitivity and poor stability. Extended gate field effect transistor (EGFET), which separates the sensitive film and transistor, is able to greatly improve the sensing performances. This work investigates the pH sensing performance of EGFET with zinc oxide (ZnO) as the active film. The pH sensitivity and current sensitivity of ZnO are studied and analyzed. The sensitivity is excellent and the data linearity is good (0.99). The expected effect of the experiment is achieved.