Study of Thin Barrier GaN Biosensor with Improved Sensitivity

The sensitivity of GaN biosensor device is directly related to transconductance (gm) of the HEMT device. In this paper, by applying with AlGaN/GaN material of thin AlGaN barrier and appropriately Al composition, the maximum transconductance (gm,max) is shifted near the zero gate voltage spontaneously. The sensitivity of the biosensor can be improved without gate reference electrode. The sensitivity of 0.35 mA/pH in pH detection and 1pg/ ml in protein detection is achieved.