ABSTRACT

This chapter discusses electrochemical sensors used for determining serum metabolites. It focuses on enzyme-based biosensors or electrochemical quantitative determination of serum metabolites. Biomolecules such as enzymes, DNA, antigen, antibody, and aptamers modified electrodes are a striking choice due to ease of fabrication, rapidity, high specificity, less pretreatment, and no requirement of skilled personnel. Electrochemical sensors monitor the current generated when electrons are exchanged either directly or indirectly between a biological system and an electrode. Biosensors can be categorized according to their transducing system. On the basis of the transducer assembly, biosensors are of the following types: field effect based, optical, piezoelectric, calorimetric, and electrochemical. Conductometric biosensors entail either consumption or production of charged species and lead to a global change in the ionic composition of the tested sample. Thus, conductometric biosensors can detect any reactive change occurring in a solution. Formaldehyde, pesticides, insecticides, and nitrate biosensors are also developed conductometrically.