(A) dielectric modulated field effect transistor with suspended gate for detection of avian influenza

Abstract

For utilizing the advantages of nanoscale for biodetection, many researchers focused on nanowire or nanotube based sensors. However, these techniques need to overcome process compatibility with exiting integrated circuit or lab-on-a-chip technology. With this perspective, we recently reported the dielectric-modulated field effect transistor (DMFET) using partial nanogap with gold gate to check possibility for biosensor application. To achieve more stable, controllable, opened fluidic structure and better complementary metal-oxide-semiconductor (CMOS) compatibility, we introduce a suspended gate DMFET with totally opened nanogap underneath poly-silicon gate. We demonstrated the dramatic threshold voltage shift by the antigen-antibody interaction between the avian influenza surface antigen (AIa) and its antibody using the silicon binding affinity, and it was verified with recovery and control experiments. The molecular binding characteristic of the inside of the nanogap was studied on concentration and width dependency. The nanogap technique based on DMFET enables for us to devise the sensor directly addressable with on-chip electronic circuit for label free infectious disease detection and other diagnostics.