An amperometric glucose electrode based on carbon paste, chemically modified with glucose dehydrogenase, nicotinamide adenine dinucleotide, and a phenoxazine mediator, coated with a poly(ester sulfonic acid) cation exchanger
✍ Scribed by Gudrun Bremle; Björn Persson; Lo Gorton
- Publisher
- John Wiley and Sons
- Year
- 1991
- Tongue
- English
- Weight
- 996 KB
- Volume
- 3
- Category
- Article
- ISSN
- 1040-0397
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✦ Synopsis
An amperometric glucose electrode is described based on carbon paste chemically modified with glucose dehydrogenase, nicotinamide adenine dinucleotide, and a mediator, Meldola Blue. The surface of the chemically modified carbon paste electrode (CMCPE) is protected by coverage with a poly(ester sulfonic acid) cation exchanger to form a membrane, which prevents the aqueous soluble species from dissolving out of the CMCPE. The CMCPE was investigated in the flow-injection analysis operation. Linear calibration curves for glucose were obtained between 100 p M and 20 mM glucose at +I00 mV versus Ag/AgCl. The sample throughput was 40 h-l. The electrodes remained stable for about 2 weeks.
WTRODUCTION
Glucose dehydrogenase (GDH) is a redox enzyme that has been used in only a few instances for the construction of amperometric glucose sensors [l-111. The enzyme depends on the soluble cofactor nicotinamide adenine dinucleotide (NAD+) for activity, which thus must be added to the analytical system. This is obviously a drawback when constructing a compact biosensor based on this enzyme. Several attempts have been made to overcome this problem common to all dehydrogenases by, for example, immobilizing the nicotinamide cofactor to the dehydrogenase [ 12, 131, to another macromolecule