This paper presents a novel biosensor based on the improved dual-channel trench gate tunnel field-effect transistor (TFET) analyzed using 2D simulations in ATLAS, showcasing exceptional performance characteristics in terms of Ion/Ioff ratio and sensitivity. The integration of TFET technology into biosensing applications offers significant advantages, including high sensitivity, low power consumption, and enhanced detection capabilities. Leveraging the unique design of the dual-channel trench gate structure, we have achieved an impressive Ion/Ioff ratio of 1014, ensuring minimal leakage current and improved energy efficiency for the biosensor. Furthermore, the biosensor exhibits a sensitivity of 1013, enabling accurate and reliable detection of target biomarkers or analysts. Our study includes a comprehensive analysis of the biosensor’s performance current–voltage (I–V) behavior and transfer characteristics, as well as its response to specific target molecules. Through extensive simulations and optimizations, we highlight the effectiveness of the improved dual-channel trench gate TFET-based biosensor in achieving superior performance compared to conventional biosensor designs. The proposed biosensor holds great potential for diverse applications, including medical diagnostics, environmental monitoring, and food safety, by providing a robust and highly sensitive platform for precise analyst detection.