Real-time sensing of hepatitis B virus X gene using an ultrasensitive nanowire field effect transistor

Devices based on semiconducting nanowires (NWs) are functioning as highly sensitive and selective sensors for the label-free detection of biological and chemical species. This paper demonstrates a novel back-gated silicon NW field effect transistor (NWFET) for gene detection. The fabricated NWFET was employed as the biomolecule sensor for the early, real-time, and label-free screening of hepatitis B virus (HBV) X gene. The DNA fragment in HBV demonstrates the linearity from 10 fM to 1 pM, of which the detection limit is estimated to be about 3.2 fM. The obtained results also show that the NW-based sensor can distinguish the difference between the complementary and 1-base mismatch DNA. The back-gated NW FET exhibits a label-free, highly sensitive, and selective biosensor for gene detection, which also provides a possibility of multiple chemical and biological species detection with sensor array in an integrated chip.