Gros P, Comtat M. A bioelectrochemical polypyrrole-containing Fe(CN)6(3-) interface for the design of a NAD-dependent reagentless biosensor.
Biosens Bioelectron 2005;
20:204-10. [PMID:
15308223 DOI:
10.1016/j.bios.2004.02.023]
[Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2003] [Revised: 02/10/2004] [Accepted: 02/10/2004] [Indexed: 10/26/2022]
Abstract
Ferricyanide ions were immobilized on a platinum electrode surface by means of an electrochemically grown polypyrrole film. The entrapped Fe(CN)6(3-)/Fe(CN)6(4-) redox system displayed a high heterogeneous electron transfer rate. The resulting modified electrode was efficient for the ferricyanide-mediated NADH oxidation catalyzed by a diaphorase. The bioelectrochemical interface was applied to the design of a reagentless amperometric D-lactate biosensor. A weakly polarized two polypyrrole-containing Fe(CN)6(3-) modified electrode system was involved without any reference. An enzymatic solution containing D-lactate dehydrogenase, diaphorase and NAD-dextran was further confined on the sensing electrode using a semi-permeable membrane. The sensitivity and the response time of the reagentless biosensor were similar to those of the analogous sensor working with soluble mediator and cofactor, i.e. 25 microA mM(-1) cm(-2) and 120 s, respectively. The other analytical performances were less satisfactorily: the detection limit was 5 x 10 mmol L(-1) and the linearity range was comprised between 0.1 and 0.5 mmol L(-1).
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