[chapter] Design of FET Biosensors

Khuraijam Nelson Singh¹ and Pranab Kishore Dutta¹

Chapter 8: Analytical Design of FET-Based Biosensors

in Advanced VLSI Design and Testability Issues; Eds: Suman Lata et all.

CRC Press, 19 Aug 2020; 360 pages

¹NERIST, Arunachal Pradesh, India

Abstract: Research on biosensors has seized the interested researchers over the past few decades due to their various advantages and applications. They are used in the discovery of drugs, monitoring of diseases, agriculture, food quality control, industrial wastage monitoring, military, etc. The sensing analyte is the main element that differentiates a biosensor from the other physical/chemical sensors. In general, the biosensor is a device that is used to detect an analyte using a biosensitive receptor. Its main components are as follows:

• Analytes: The substance that is intended to be detected, such as glucose in a glucose sensor, ammonia in ammonia sensor, and so on.
• Bioreceptors: The bioreceptors are biosensitive elements used to detect target analytelbiomolecule. They are sensitive to the analytes of interest. Some examples of bioreceptors are antigen, DNA, enzyme, and so on.
• Transducers: The elements that are used to convert energy from one form to another are called transducers. In a biosensor, the interaction of analytes and bioreceptors produces changes in the form of heat, gas, light, ions, or electrons. These changes are then converted into a quantif‌iable form by the transducer. Usually, the output of the transducer is in the form of electrical or optical signals, and the generated signal is proportional to the interaction between the analyte and the biosensor.

FIG: Schematic diagram of ion-sensitive f‌ield-effect transistor (ISFET)