Design and Fabrication of Highly Performance EGFET and Application in Thrombin Detection

In this article, a high-performance extended-gate field-effect transistor (EGFET) with a replaceable sensing area was designed using HfO2 and In2O3. A 3-D simulation model was built based on Silvaco technology computer aided design (TCAD) software. This model could capture the internal physical structure of the device accurately, to guide the design of EGFETs. Based on the material and structure simulation analysis, the optimal simulation model was constructed. Then, the EGFET was fabricated in accordance with this model. The results demonstrated that the EGFET designed in this study exhibited high performance with pH voltage sensitivity of 110.91 mV/pH, linearity (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}^{2}$ </tex-math></inline-formula>) of 97.67%, and relative standard deviation (RSD) of threshold voltage of 3.51%. Furthermore, thrombin (Tob), which requires high detection accuracy and a wide concentration range, was chosen as the detecting target biomarker to validate the performance of EGFETs in detecting trace markers. A handheld device was fabricated based on the EGFET to realize the detection of Tob concentration in the range of 1–10 000 pM (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}^{2}$ </tex-math></inline-formula> =95.64%), indicating the excellent performance and enormous potential of the EGFET.