Advanced FET Biosensors: Design, Materials, and Biomedical Applications

Field-Effect Transistor (FET) biosensors have emerged as powerful analytical tools with remarkable sensitivity, rapid response, and compatibility with miniaturized platforms. Recent developments in advanced nanomaterial synthesis, innovative MOSFET architectures, surface functionalization techniques, integrated real-time monitoring, and specialized nanoscale fabrication have significantly improved the performance. This review presents a comprehensive analysis of the state-of-the-art high-sensitivity FET biosensors, focusing on structural advancements, material optimization, and application-specific performance. The study emphasizes the incorporation of two-dimensional (2D) nanomaterials, dual-gate and gate-all-around (GAA) architectures, and CMOS integration techniques that have enabled real-time, ultra-sensitive detection of various biomolecules. Furthermore, the relevance of high-k dielectric materials, high mobility semiconductors, and biocompatible coatings is highlighted to demonstrate the impact on enhancing device performance. Despite these advancements, challenges related to sensitivity, selectivity, device stability, and scalability persist. Therefore, this review outlines current research efforts aimed at overcoming these challenges, with particular attention to improving material robustness, developing novel architectures, and integrating machine learning and IoT-based analytical techniques. Future directions for the development of next-generation FET biosensors are also proposed to address industrial scalability and to enhance their applicability across biomedical, environmental, agricultural, and food industries.