4] Industrial applications of enzyme electrodes including instrumentation

Abstract

The most interesting application of immobilized enzymes is their use as the active element of an electrochemical probe or sensor. This chapter discusses the analytical principle of the enzyme electrode and its potential use as a tool for biotechnological analysis. Enzyme electrodes, which generally consist of an electrochemical sensor with an immobilized enzyme in close contact, have several advantages over other methods of analysis: (1) immobilization generally stabilizes the enzyme, enables repeated measurements, and offers the possibility of continuous analysis, which is a major advantage in any process control, and (2) classical analytical procedures require the precipitation or dialytic separation of proteins. In contrast, electrochemical monitoring with enzyme electrodes can be carried out on whole fermentation juice or biological media, thus eliminating preparation of the sample. The use of gas-sensing membrane electrodes has led to the development of better enzyme electrodes, which are free of interference from ions, proteins, and electrochemically active compounds.