ABSTRACT
This chapter focuses on electrochemical biosensors based on various bioreceptors such as enzymes, DNA, and antibodies. Enzyme-based electrochemical biosensors have been exploited in various applications such as in biomedicine, food analysis, and environmental monitoring. The first step in fabricating enzymatic sensors involves preparation of a sensing interface. The second step in the fabrication of enzyme-based biosensors is the immobilization of enzymes on the surface of the electrode. A DNA biosensor is based on the principle of immobilization of a single-stranded DNA (ssDNA) on an interface, which combines with its complementary sequence according to Chargaff's rule and form a hybrid. The indirect method of DNA detection is considerably more admired than the label-free approaches because there are many more ways in which transduction can be configured with high sensitivity and selectivity. Enzyme-labeled DNA is also employed for the detection of DNA. Electrochemical immunosensors are the best among all sensors because of their high sensitivity, ease of fabrication, and specificity.
