Label-free electrical detection of deoxyribonucleic acid (DNA) hybridization was demonstrated using an AlGaN/GaN high electron mobility transistor (HEMT) based transducer with a biofunctionalized gate. The HEMT DNA sensor employed the immobilization of amine-modified single strand DNA on the self-assembled monolayers of 11-mercaptoundecanoic acid. The sensor exhibited a substantial current drop upon introduction of complimentary DNA to the gate well, which is a clear indication of the hybridization. The application of 3 base-pair mismatched target DNA showed little change in output current characteristics of the transistor. Therefore, it can be concluded that our DNA sensor is highly specific to DNA sequences.
Bibliographical noteFunding Information:
This project was funded by the United States Department of Agriculture (USDA) through Auburn University Detection and Food Safety Center (AUDFS). The authors would like to thank Dr. David Deen, SVT Associates, Inc., for his valuable comments to the manuscript and Dr. David Stanbury, Department of Chemistry and Biochemistry, Auburn University, for allowing us to use his UV-Vis spectrometer.