[19p-PB1-1~34] 12.7 Biomedical Engineering and Biochips

[19p-PB1-24] Independent Observation Method for proton concentration and Electric Potential Image by a pH Image Sensor

〇Kotaro Sakamoto¹, Yasuyuki Kimura¹, Toshihiko Noda^1,2, Kazuhiro Takahashi^1,2, Kazuaki Sawada^1,2 (1.Toyohashi Univ., 2.EIIRIS)

Keywords:pH image sensor, ISFET, ion sensitive membranes

In our previous study, we have been developing a needle type pH image sensor that can monitor hydrogen ion concentration in a living body. Since the sensors respond to both solution potential change and pH change, there is a problem that this can not be distinguished. We proposed that the principle which can calculate a solution electric potential and pH change independently from two outputs of the adjacent pixel pair of pH image sensor. The principle was confirmed using a pH image sensor of our previous work. From the output of the pixel pair when the solution potential was changed, we confirmed that the pH was constant regardless of the solution voltage. It was shown that the pH and the solution potential could be detected separately. Furthermore, it was shown that the calculation results of the solution potential and pH become more accurate as the pH sensitivity difference of the pixel pair is larger.