The Polymer Society of Korea

Abstract

Extended-gate field-effect transistors (EGFETs) are promising for real-time chemical and biosensing due to their high sensitivity and flexibility. However, their performance is often limited by the Nernst response and affected by ion screening in complex fluids. Here, we present a dual-gate (DG) EGFET platform to overcome these issues. The back-gate voltage enables capacitive coupling with the electrolyte gate, allowing precise modulation of the channel potential and amplifying the sensor’s response to surface potential changes. To ensure stability in liquid environments such as phosphate-buffered saline (PBS), we apply a self-assembled multilayer (SAML) as a passivation layer to prevent leakage current. This approach significantly improves both sensitivity and stability, demonstrating the potential of DG-EGFETs in advanced biosensing applications.