ISSN:
1040-0397
Keywords:
Enzyme reactor
;
Substrate recycling
;
Poly(1,2-diaminobenzene)film-coated electrode
;
Flow injection analysis
;
L-Lactate
;
Pyruvate
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The poly(1,2-diaminobenzene)film-coated platinum electrode was used as an amperometric detector in a flow-injection system with the lactate dehydrogenase/lactate oxidase coimmobilized reactor involving amplification by substrate recycling. Both L-lactate and pyruvate are recycled enzymatically during their passage through the enzyme reactor in the presence of reduced nicotinamide adenine dinuceotide (NADH) and oxygen in the carrier stream. As a result, a large amount of hydrogen peroxide is generated in the enzyme reactor. The poly(1,2-diaminobenzene)-coated electrode could only selectively detect the hydrogen peroxide generated in the enzyme reactor, without an increase in the base-line current owing to the direct oxidation of NADH, because the poly(1,2-diaminobenzene) film effectively prevented NADH in the carrier stream from reaching the electrode surface and allowed only the hydrogen peroxide to penetrate into the polymerized film. In the present flow-injection analysis (FIA) system, both L-lactate and pyruvate were determined with a 400-fold increase in sensitivity compared with the unamplified responses. The detection limit was 2 × 10-9 M (20 fmol) for 10 μL sample injection.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/elan.1140070418
