Surface Immobilizations of AlGaN/GaN High Electron Mobility Transistor Based Sensors

Recent progress in AlGaN/GaN HEMT sensors is reviewed in this paper. These devices can take advantage of the advantages of microelectronics, including high sensitivity, possibility of high-density integration, and mass manufacturability. HEMT sensors show promising results for protein, DNA, prostate cancer, kidney injury molecules, pH values of solutions, mercury ions as well glucose in the exhaled breath condensate. The method relies on an amplification of small changes in antibody-structure due to binding to antigens. The characteristics of these sensors include fast response (liquid phase-5 to 10 seconds and gas phase-milli-second), digital output signal, small device size (less than 100 x 100 mu m(2)) and chemical and thermal stability.