Glucose oxidase coupling with other enzymes

This is the flavoprotein glucose oxidase, and the hydrogen peroxide produced is coupled to the formation of a green d[ye using the colourless leuco-dye 2,2 -azino-di-(3-ethylbenzthiazoline) 6-sulphonate [ABTS], This simple format can be used with other enzymes that are specific for the substrate they oxidize and produce hydrogen peroxide as a product (for example, galactose oxidase, n-amino acid oxidase, monoamine oxidase etc.). 

Test strips, which are available for the determination of about ten low-molecular mass substances (metabolites, drugs, and electrolytes) and eight enzymes [356], can be considered as precursors of optoelectronic biosensors. Efficient optoelectronic sensors based on immobilized dyes have been devised for the determination of glucose, urea, penicillin, and human serum albumin [357]. Other approaches use immobilized luciferase or horseradish peroxidase to assay ATP or NADH or, when coupled with oxidases, to measure uric acid or cholesterol. These principles have not yet been generally accepted for use in routine analysis. Thermistor devices involving immobilized enzymes or antibodies for a number of clinically relevant substances have also been described. Thermometric enzyme linked immunosorbent assays are being routinely employed for monitoring the production of monoclonal antibodies. 

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