Impedance-based biosensors

Abstract Impedimetric biosensor is commonly applied for analysis of a wide variety of physical and chemical properties. Impedimetric techniques have been employed in monitoring different catalytic enzymatic reactions for identification of binding of specific proteins, nucliec acids, antibodies, cell receptors, or other biomolecules. In this process, impedance of any system under examination is measured over a wide range of alternating current frequencies. Other than different biomecules, this method is also important for assessment of fuel cells coating as well as in corrosion phenomena. The biological reactions occurring on the surface of electrodes is monitored through impedimetric measurements. Generally, biological molecules like enzymes, antibodies, nucleic acids, cells, etc., are immobilized on the surface of impedimetric biosensor electrodes. Various research groups have explored the interaction between the biomolecules with the conductive or semiconductive surface of biosensors. Impedimetric sensors are available in different forms depending on the target molecules under investigation. Some types of biosensors are enzyme- and protein-based sensor, immuno-biosensors, aptamer-based biosensors, cell-based sensors, etc. In this chapter, we will discuss these biosensor types, their applications in biomedical fields, and recent developments in the area of impedimetric biosensors.