Highly Sensitive Detection of Deoxyribonucleic Acid Hybridization Using Au-Gated AlInN/GaN High Electron Mobility Transistor-Based Sensors

摘要

Gallium nitride-(GaN) based high electron mobility transistors (HEMTs) provide a good platform for biological detection.In this work,both Au-gated AlInN/GaN HEMT and AlGaN/GaN HEMT biosensors are fabricated for the detection of deoxyribonucleic acid (DNA) hybridization.The Au-gated AlInN/GaN HEMT biosensor exhibits higher sensitivity in comparison with the AlGaN/GaN HEMT biosensor.For the former,the drain-source current (VDs =0.5 V) shows a clear decrease of 69μA upon the introduction of 1 μmolL-1 (μM) complimentary DNA to the probe DNA at the sensor area,while for the latter it is only 38μA.This current reduction is a notable indication of the hybridization.The high sensitivity can be attributed to the thinner barrier of the AlInN/GaN heterostructure,which makes the two-dimensional electron gas channel more susceptible to a slight change of the surface charge.