Colon cancer has a survival rate of 90% or more when detected early, but the current clinical diagnostic methods of identifying colon cancer such as optical screening and biopsy for polyp samples have difficulties in early diagnosis due to low sensitivity and complex process. In this study, we developed a field-effect transistor(FET)-based biosensor with high sensitivity and specificity to quantitatively analyze colon cancer biomarkers in serum samples. Conventional FET-based sensors have limitations to detect target molecules in serum due to short Debye length and high noise signal from high concentrations of ions and many interfering species. In this study to circumvent these issues we propose a new dual-gate FET based biosensors featuring 4-channel disposable sensing module(DSM). We successfully demonstrated that our new biosensor can facilitate a fg/ml level detection of biomarkers in serum.