It is of the utmost importance to rapidly detect and identify bacterial pathogens contained in food. Numerous studies have been performed to develop a biosensor to detect the biopathogens contained in food. Due to its high specificity, hybridization-based DNA sensing mechanisms have of high merit. Among the DNA hybridization biosensors, field effect transistor (FET) based sensors are of interest due to its rapidness in detection and label-free use. AlGaN-based high electron mobility transistor (HEMT) is a special type of a FET which exhibits a high charge sensitivity due to the ample existence of 2 dimensional electron gas (2DEG) in the quantum well transistor channel. In our research, we have fabricated AlGaN-based HEMT DNA sensor and has successfully demonstrated the DNA hybridization. In order to enhance specificity maintaining its sensitivity, an amine-based chemistry was used. A DNA with a sequence which represent that of salmonella were used as a probe. A 3 base-pair mismatched DNA was used as a control. A DNA with a complementary sequence was used as a target. The DNA sensor showed a significant current decrease when a complimentary DNA was applied to the gate well while a substantially small current reduction was observed for the introduction of 3 base pair mismatched DNA. Therefore, it was concluded that the AlGaN-based HEMT DNA sensor with amine-based chemistry exhibits high specificity in detection.

Ref) Resham Thapa, Siddharth Alur, Kyusang Kim, Fei Tong, Yogesh Sharma, Moonil Kim,

Claude Ahyi, Jing Dai, Jong Wook Hong, Michael Bozack, John Williams, Applied Physics Letters 100, 232109 (2012).