Compound-Semiconductor-Based Field-Effect Transistors for Ultrasensitive Biomolecule Sensors.

Compound-semiconductor-based field-effect transistor (FET) biosensors have emerged as a powerful platform for ultrasensitive and selective biomolecule detection, offering transformative potential for personalized healthcare and real-time environmental monitoring. This review comprehensively discusses recent advances in the development and integration of compound semiconductor materials for electronic biosensing applications, including two-dimensional transition metal dichalcogenides, such as molybdenum disulfide, layered III-VI semiconductors, such as indium selenide, and oxide-based II-VI semiconductors, such as zinc oxide and indium oxide. Key detection mechanisms, emphasizing bandgap modulation and charge-absorption-induced carrier density variations, are explored to elucidate the underlying principles of high sensitivity and specificity. The paper also reviews key fabrication strategies for flexible and wearable FET devices, highlighting their integration with microfluidics and bioreceptors for enhanced functionality. Practical applications in point-of-care diagnostics, implantable healthcare monitoring, wearable sensor technologies, and environmental safety assessments are critically evaluated. The review unifies material-level physics, interface chemistry, and device-level engineering to establish a cohesive framework explaining how compound semiconductors uniquely enable bandgap-modulated biosensing. The review further identifies cross-platform design principles and emerging trends, particularly toward scalable fabrication, multiplexed detection, and clinically deployable bioelectronic systems. By outlining key challenges and opportunities in material innovation and system integration, this review provides a forward-looking roadmap for advancing compound-semiconductor FETs toward next-generation diagnostic and continuous monitoring technologies.