Fast Electrical Detection of Carcinoembryonic Antigen Based on AlGaN/GaN High Electron Mobility Transistor Aptasensor

As one of the most important tumor-associated antigens of colorectal adenocarcinoma, the carcinoembryonic antigen (CEA) threatens human health seriously all over the globe. Fast electrical and highly sensitive detection of the CEA with AlGaN/GaN high electron mobility transistor is demonstrated experimentally. To achieve a low detection limit, the Au-gated sensing area of the sensor is functionalized with a CEA aptamer instead of the corresponding antibody. The proposed aptasensor has successfully detected different concentrations (ranging from 50 picogram/milliliter (pg/ml) to 50 nanogram/milliliter (ng/ml)) of CEA and achieved a detection limit as low as 50 pg/ml at V_\rm ds=0.5 V. The drain-source current shows a clear increase of 11.5 \muA under this bias.