RF detection of DNA based on CMOS inductive and capacitive sensors

New inductive and capacitive sensors have been developed in order to electrically detect specific DNA sequences on a low cost CMOS-compatible technology. The sensors are made of Al electrodes coated with Al2O3 surface permitting efficient on-chip single strand DNA capture probe thetering. We detect a shift of the self-resonance frequency of about 5.6 GHz (25%) with a spiral inductor upon hybridation with complementary single strand DNA target probe at a 5 nM concentration. For interdigitated capacitors, we detect a shift of 4.2 GHz (52%). These results open DNA detection possibilities comparable to present optical detection methods.