Résumé
The electropolymerization of a flavin reductase (Fre) - amphiphilic pyrrole ammonium mixture previously adsorbed on the electrode surfaceprovides an efficient bioelectrode for the amperometric detection of NADH and NADPH. The bioelectrode response was based on the oxidation at-0.1 V vs. SCE of the enzymically generated dihydroriboflavin. The sensitivity and detection limit of the bioelectrode were 29 mAM-' cm-' and0.2pM for NADH and €5.8mAM-' cm-' and 0.4pM for NADPH. The coimmobilization of Fre and a lactate dehydrogenase leads to adehydrogenase-based biozlectrode for the determination of lactate in the presence of riboflavin and NAD'. With laponite additives into thepolypyrrole host matrix, the sensitivity and the detection limit of the bioelectrode for lactate are 11.7 m.4M-I cm? and 1 pM respectively. Owing tothe negative value of the applied potential for the oxidation of riboflavin, the response of the bienzyme electrode remains insensitive to interferentslike ascorbate, urate and acetaminophen.