Functionalized Nanomaterials for Designing Nano/Micro Biologically Sensitive Field-Effect Transistors (Bio-FETs)

Nanomaterial-based biosensors and biologically sensitive field effect transistors (bio-FETs) have demonstrated tremendous growth in the domain of point-of-care testing to facilitate personalized medicine and therapy. Nanomaterials, including two-dimensional inorganic and organic frameworks, demonstrate environment-dependent conductivity. Higher surface area-to-volume ratio, structure and composition variability, and the defect chemistry of nanostructures have a significant impact on the electroanalytical properties of the devices. Bio-FETs, coupled with functionalized nanomaterials, offer a wide range of benefits over conventional biosensors, including label-free detection. Functionalization of nanostructures in bio-FETs manifests higher sensitivity, selectivity, ultra-low detection limits, stability, precision, and ease of integration with portable and wearable platforms. To this date, bio-FETs are employed for sensing viruses, biomolecules, nucleic acids, whole cells, and various protein biomarkers, including neurotransmitters. This chapter details the basic concepts of biosensing, the evolution of bio-FETs, and the components that govern the device’s performance. It offers a detailed discussion of various nanomaterial fabrication methods (both functionalized and pristine) and their integration with biological probes (enzymes, aptamers, antibodies, etc.) for constructing efficient transduction elements. It envisages the design aspect of bio-FETs and their integration with the nano/molecular transducers. The chapter concludes with case studies, benefits, and challenges of a few nanomaterial-based bio-FETs.