Disposable Gate AlGaN/GaN High-Electron- Mobility Sensor for Trace-Level Biological Detection

In this letter, we propose a highly reliable biosensor based on the disposable gate (DG) AlGaN/GaN high-electron mobility transistor (HEMT) sensor. The greatest advantage of this device is that the HEMT structure and the sensing structure containing the sensitive membrane are separate, overcoming the drawback of being easily contaminated in a biochemical environment. The DG structure HEMT sensor exhibited stable and rapid response to the addition of different concentrations of the prostate-specific antigen (PSA), and the achieved limit of PSA detection was as low as 100 fg/mL. It was also found that the DG AlGaN/GaN HEMT sensor shows good linearity and specificity. These results demonstrate the DG HEMT sensor can be considered to be a promising biosensor platform for practical application in disease diagnosis.