Sensing Beyond the Debye Length: Development of a 32 × 32 CMOS DNA Sensor Array

This letter reports a large complementary metal-oxide semiconductor DNA array with more than 1000 sensors to demonstrate sensitive and wide-range detection under strong Debye charge screening. To this end, we electrically modulated the extended-gate field effect transistors (FETs) under study to extend the Debye length and compare results at different frequencies. Operation at higher frequencies showed better DNA sensitivity than at low frequencies. The array exhibited a pH sensitivity of 38 mV/pH in floating-gate potential changes. Detection of DNA hybridization showed a sensitivity of 19 mV/log
₁₀
[DNA] in 1× phosphate buffered saline from 0.1 fM to 10 nM at 15 MHz.