Electrical detection of deoxyribonucleic acid hybridization with AlGaN∕GaN high electron mobility transistors

TLDR

The Au‑gated AlGaN/GaN HEMT provides a binding layer on the AlGaN surface for hybridization of target DNA. Au‑gated HEMTs were functionalized with 3′‑thiol‑modified oligonucleotides and used to detect probe‑target DNA hybridization through changes in drain‑source current. X‑ray photoelectron spectroscopy confirmed covalent attachment of thiol‑modified DNA to gold, and the HEMT drain‑source current dropped by 115 µA upon introduction of matched target DNA, demonstrating the sensor’s potential for DNA detection.

Abstract

Au-gated AlGaN∕GaN high electron mobility transistor (HEMT) structures were functionalized in the gate region with label-free 3′-thiol-modified oligonucleotides. This serves as a binding layer to the AlGaN surface for hybridization of matched target deoxyribonucleic acid (DNA). X-ray photoelectron spectroscopy shows the immobilization of thiol-modified DNA covalently bonded with gold on the gated region. Hybridization between probe DNA and matched or mismatched target DNA on the Au-gated HEMT was detected by electrical measurements. The HEMT drain-source current showed a clear decrease of 115μA as this matched target DNA was introduced to the probe DNA on the surface, showing the promise of the DNA sequence detection approach for biological sensing.