Journal article
Dual-enzyme fiber-optic biosensor for glutamate based on reduced nicotinamide adenine dinucleotide luminescence
Analytical chemistry (Washington), Vol.64(9), pp.1051-1055
05/01/1992
DOI: 10.1021/ac00033a016
PMID: 1350433
Abstract
Response characteristics are presented for a dual-enzyme fiber-optic biosensor for glutamate. An enzyme layer composed of glutamate dehydrogenase (GDH) and glutamatepyruvate transaminase (GPT) Is used to produce reduced nicotinamide adenine dinucleotide (NADH) at the tip of a fiber-optic probe. NADH luminescence Is monitored through this probe and the measured fluorescence Intensity Is related to the concentration of glutamate. GDH catalyzes the formation of NADH, and GPT drives the GDH reaction by removing a reaction product and regenerating glutamate. Optimal response Is obtained In a pH 7.4 Tris-HCI buffer maintained at 25°CIn the presence of 4 mM NAD+and 10 mM L-alanine. The temperature profile reveals a strong negative temperature effect which Is attributed to the temperature dependency of NADH luminescence. Under optimal conditions, the sensor sensitivity Is 0.127 nA/μ M over the 1-10μ M concentration range, the detection limit Is 0.13μ M, and response times range from 4 to 8 min. The sensor response Is stable for 12 days when stored at 4° C.Selectivity for glutamate Is excellent over most of the common amino acids as well as ascorbic acid, uric acid, taurine, and GABA. Only slight responses were observed for glutamine and lysine. The effect of ammonia on the glutamate response was found to be minimal at total ammonia nitrogen concentrations as high as 200μ M. © 1992, American Chemical Society. All rights reserved.
Details
- Title: Subtitle
- Dual-enzyme fiber-optic biosensor for glutamate based on reduced nicotinamide adenine dinucleotide luminescence
- Creators
- Ae June WangMark A Arnold
- Resource Type
- Journal article
- Publication Details
- Analytical chemistry (Washington), Vol.64(9), pp.1051-1055
- Publisher
- American Chemical Society
- DOI
- 10.1021/ac00033a016
- PMID
- 1350433
- ISSN
- 0003-2700
- eISSN
- 1520-6882
- Language
- English
- Date published
- 05/01/1992
- Academic Unit
- Center for Biocatalysis and Bioprocessing; Fraternal Order of Eagles Diabetes Research Center; Chemistry
- Record Identifier
- 9984217558002771
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