Glucose determination with chemically modified electrodes

All electrodes react with their environment via the surfaces in ways which will determine their electrochemical performance. Properly selected surface modification can effectively enhance the electrode heterogeneous catalysis property, especially selectivity and activity. The bulk materials can be chosen to provide mechanical, chemical, electrical, and structural integrity. In this part, several surface modification methods will be introduced in terms of metal film deposition, metal ion implantation, electrochemical activation, organic surface coating, nanoparticle deposition, glucose oxidase (GOx) enzyme-modified electrode, and DNA-modified electrode. 

In 1988, a pioneering work dealing with electrode characteristics of an immobilized enzyme chemically modified electrode based on bilayer-film coating for amperometric determination of glucose was reported. In this work, a substrate was coated with two kinds of polymeric films in a bilayer state, that is, first with the cobalt tetrakis(o-aminophenyl)porphyrin polymer film and then with the enzyme film consisting of bovine serum albumin and glucose oxidase that were... 

What one can consider as the first electrochemical sensor, i.e., a modified electrode surface dedicated to a specific target analyte, was a platinum electrode, covered by a protective membrane, the Clark electrode, for the determination of O2 in blood.The first biosensor was based on the determination with such Clark electrode of O2 depletion induced by glucose oxidase activity in the presence of glucose.These two examples show the importance of platinum as electrode material. It will be seen below that gold was also widely used for the development of chemically modified electrodes, especially due to the strong interaction with thiol-functionalized organic molecules allowing the formation of self-assembled monolayers (SAM). ... 

H. J. Wieck, G. H. Heider, Jr., and A. M. Yacynych, Chemically Modified Reticulated Vitreous Carbon Electrode with Immobilized Enzyme as a Detector in Flow Injection Determination of Glucose. Anal. Chim. Acta, 158 (1984) 137. 

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