[12p-S301-1~15] 6.2 Carbon-based thin films

△ [12p-S301-13] PH Sensitivity of Diamond Elecrolyte Solution Gate FET with Stainless Steal Vessel as Gate at High Temperature

〇Reona Nomoto¹, Shuto Kawaguchi¹, Hirotaka Sato¹, Teruaki Takarada¹, Yu Hao Chang¹, Hiroshi Kawarada^1,2 (1.Waseda Univ., 2.ZAIKEN)

Keywords:Diamond, FET, pH sensor

In this study, we verified the pH sensitivity of oxygen-terminated diamond SGFETs in high-temperature solutions (80 ° C). As the gate electrode, a glass electrode (Ag/AgCl) and a stainless steel container (Vessel Gate) were used. The results showed that when the gate electrode was Ag/AgCl, the diamond SGFETs was less sensitive to pH. Therefore, by combining the diamond SGFETs with the highly pH-sensitive Vessel Gate, a high pH sensitivity of -50 mV / pH, which is close to the Nernst response, was obtained. From the above, it was found that the oxygen-terminated diamond SGFETs becomes insensitive to pH at high temperature (80 ° C), and by combining with Vessel Gate, a highly sensitive all-solid-state glassless pH sensor can be realized as a whole.