ABSTRACT
Microfluidics is the field dealing with the study of fluid flow restricted to volumes typically in the range of microliters to picoliters. This chapter reviews the various microfluidic biosensors based on impedance measurement for diagnostic applications like the detection of DNA, bacteria, viruses, and proteins in lab settings as well as under point-of-care conditions. Electrochemical impedance spectroscopy (EIS) is an excellent sensing method used to assess the changes in the interfacial properties related to biochemical sensing activities at the electrode surface. EIS can be classified into faradaic and non-faradaic electrochemical impedance. Non-faradaic impedance is executed in the absence of a redox probe. EIS integrated with microfluidics has been used for the quantitative and qualitative detection of pathogenic and nonpathogenic microorganisms, DNA, proteins, cancer biomarkers, pesticides, food contaminants, etc. The chapter focuses mainly on the various impedimetric biosensors with a detailed discussion of the integrated microfluidics aspects utilized for the fabrication of the devices. The biosensors discussed have been classified based on their applications. The fabrication methods have been briefly explained, and the performance of biosensors has been summarized.
