Sensing Beyond the Debye Length: Development of A Highly Sensitive, Wide-Range Cmos Dna Sensor Array

This work presents a large complementary metal-oxide semiconductor (CMOS) deoxyribonucleic acid (DNA) array consisting of over 1,000 sensors, which was used to demonstrate sensitive and wide-range detection under strong Debye charge screening. The fabricated extended-gate field effect transistors (EGFETs) were electrically modulated to extend the Debye length, and the results were compared at different frequencies. The experiment showed that operation at higher frequencies led to better DNA sensitivity than at lower frequencies. The detection of DNA hybridization showed a sensitivity of 19.3 mV/log
10
[DNA] in floating-gate potential changes from 0.1 fM to 10 nM at 15 MHz. The array also exhibited a pH sensitivity of 38 mV/pH.