Comprehensive chemistry for electrochemical enzyme biosensors

Abstract

Research on electrochemical biosensors that use biomolecules as biorecognition elements is about to reach 60 years since its inception. In recent years, biosensors have attracted attention in a wide range of fields such as food science, environmental science, and medicine. Knowledge of enzymes, immobilization methods, and conductive compounds is essential in designing new enzyme biosensors; thus, this chapter focuses on these discussions from an enzymatic and organic chemistry perspective. Most of the enzymes used in biosensors are oxidoreductases, including oxidases and dehydrogenases, and hydrolases are often used in combination with oxidoreductases. Enzyme immobilization methods include covalent bonding, crosslinking, adsorption, affinity bonding, and entrapment, which are branched into more detailed methods. Electron-transfer mediators and conducting organic polymers have become explosives that produce a wide variety of enzyme biosensors. In particular, third-generation biosensors based on the principle of direct electron transfer have made remarkable progress in recent years, and their future prospects are drawing attention.