Analysis and experimental verification of DNA single-base polymerization detection using CMOS FET-based redox potential sensor array

We report a method for detecting DNA single-base polymerization using a complementary metal oxide semiconductor (CMOS) field effect transistor (FET)-based redox potential sensor array. The redox potential detection method has the possibility of high-accuracy detection of DNA polymerization compared with other FET-based methods because this method is not affected by buffer conditions. First, we demonstrated pyrophosphate (PPi) detection assuming that DNA polymerization occurred. This result showed a sensitivity of −12.3 mV/decade for a logarithmic concentration of PPi in the range of 0.05-1 mM. To investigate the appropriateness of this measurement result, we conducted a theoretical analysis using the equilibrium constant. Next, we demonstrated DNA single-base polymerization detection. There was a 5.65 mV difference between the reaction solutions with a mismatched deoxynucleotide triphosphate (dNTP) and with a matched dNTP. This voltage difference is reasonable given the PPi detection result, which achieves a sufficient signal-to-noise ratio (SNR) of more than 20 dB.