Immobilization of Enzymes on Electrodes

This chapter focuses on the four main immobilization techniques used in the development of enzyme electrodes: adsorption, entrapment, covalent coupling, and cross-linking. The performance of the immobilization method depends on the enzyme and each method has both advantages and drawbacks. Loss of the activity results from the change in enzyme conformation depending on the method of immobilization as well as modification of the microenvironment (i.e., local pH of the enzyme). The activity of the immobilized enzyme decreases as a result of barrier of diffusion, which slows down or prevents the substrate from reaching the active site of the enzyme. The development and the characteristics of an acetylcholinesterase biosensor are described