Glucose quantitation using an immobilized glucose dehydrogenase enzyme reactor and a tris(2,2′-bipyridyl) ruthenium(II) chemiluminescent sensor
✍ Scribed by Alice F. Martin; Timothy A. Nieman
- Publisher
- Elsevier Science
- Year
- 1993
- Tongue
- English
- Weight
- 654 KB
- Volume
- 281
- Category
- Article
- ISSN
- 0003-2670
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✦ Synopsis
A flow-injection analysis detection method for ghrcose is presented which is based on oxidation of ghrcose by glucose dehydrogenase with concomitant conversion of NAD+ to NADH followed by chemiluminescent detection of NADH. The glucose dehydrogenase is immobilized via glutaraldehyde crosslinking to controlled pore glass to form an immobilized enzyme reactor. The chemiluminescent reagent, tris(2,2'-bipyridyBruthenium(I1) [Ru(bpy)$+] is immobilized in a Nafion film coated on a platinum electrode to form a regenerable chemiluminescent sensor. The immobilized Ru(bpy)$+ is oxidized to Rdbpy)$+ yield light and Ru(bpy)$+. Ru(bpy):+ which then reacts with NADH produced by the enzyme reactor to is thus recycled and made available again. Conditions for optimum enzyme reactor efficiency and chemihuninescent detection are determined and reported for pH (about 6.51, flow-rate (2 ml mm-'), and NAD+ concentration (l-2.5 mM). At the optimum conditions a working curve is constructed where the upper limit for glucose detection is dependant on NAD+ concentration and lower detection limit is 10 PM glucose. Signal reproducibility is l-2% relative standard deviation. The method is very selective for glucose; some interference is seen from uric acid, ascorbic acid and catechol as well as species (such as oxalate and aliphatic amines) already known to chemiluminesce with the Ru(bpy)g+ sensor.