The Physics and Operating Principles of Field-effect Transistor-based Biosensors

Abstract

The development of field-effect transistor (FET) biosensors in recent years has been tremendous due to their advantages such as good scalability, high sensitivity, real-time detection, inherent amplification, and lower power requirements with the possibility to produce information in a fast and straightforward manner compared to conventional assays. In order to demonstrate the potential of FET-based biosensors, researchers have employed different biomolecular targets with varied sizes from the micro- to nanoscale such as nucleic acids, proteins, cells, antibodies, and antigens that have been used as biomarkers for clinical diagnosis of diseases. In this chapter, we elucidate the basic operating mechanism of FET technology along with its different types of FET-based biosensor devices such as ion sensitive field-effect transistors (ISFETs), separative extended gate field-effect transistors (SEG-FETs), floating-gate FETs, and dielectric modulated FETs (DM-FETs). The existence of well-established semiconductor technology has significantly improved the manufacturing process of biologically sensitive field-effect transistors (BioFETs) and will pave the way to commercial devices. We also discuss the potential and challenges of FET-based biosensors for various healthcare applications and their opportunities to become the next generation point-of-care (POC) testing.