ISSN:
1040-0397
Keywords:
Lactate determination
;
Amperometric biosensor
;
Enzyme electrode
;
Reticulated vitreous carbon
;
RVC
;
NAD+-analog
;
Coenzyme regeneration
;
Mediator
;
Meldola Blue
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
A NAD+-analog was coimmobilized with lactate dehydrogenase (LDH) on reticulated vitreous carbon (RVC) to give an amperometric lactate biosensor. Both LDH and the NAD+ -analog were bound covalently with carbodiimide to the surface of the porous RVC-material. The electrode was operated in a FIA-arrangement in the presence or absence of a soluble mediator. Meldola Blue. The stability was poor when the electrode was operated at +400 mV (vs. Ag/AgCl) in the absence of mediator but improved most significantly in the presence of 5 μM mediator, so that 65% of the original activity remained after 16 days. The amperometric currents were smaller with regeneration by mediator at -100 mV than with direct electrochemical oxidation at +400 mV, indicating that the additional steps slow down the reaction rate. Linear calibration plots were obtained from the detection limit, 1 μM, to 500 μM lactate with 5 μM mediator, reoxidized at -100 mV. The sample throughput was about 60 h-1.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/elan.1140090703
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