This work proposes a charge-trap-flash (CTF) type ion-sensitive-field-effect transistor (ISFET) as a high-performance pH sensor platform with high sensitiv-ity. The proposed platform overcomes the low sensitivity problem (~59 mV/pH) of conventional ISFETs by utiliz-ing the resistance coupling effect via channel resistance modulation. CTF-type ISFET enables accurate pH detec-tion and high sensitivity, which was demonstrated through excellent signal amplification and sensitivity control. The proposed pH sensor platform is expected to be widely used in next-generation biosensors for micro-potential analytes detection.