Synergetic effect for NADH oxidation of ferrocene and zeolite in modified carbon paste electrodes. New approach for dehydrogenase based biosensors.
The development of electrochemical biosensors using dehydrogenases associated with the corresponding cofactor is strongly related to the better understanding of NADH oxidation at the electrode surface. The aim is to lower the necessary overvoltage and consequently to escape interferences and electrode fouling. In this paper, we show that carbon paste electrode (CPE) modified with NaY zeolite fulfils this requirements thanks to its hydrophilic surface. Oxidation of NADH at ferrocene (FcH) modified carbon paste electrode exhibits a rather slow electrocatalytic effect. We demonstrated the existence of synergetic effect on the electrocatalytic oxidation of NADH when the CPE is doped with zeolite (NaY) and FcH mediator or with the zeolite exchanged beforehand with the mediator (Y-Ferricinium, YFcH). This cumulative effect permits to reach high sensitivity for NADH detection and offers new way for the development of enzymatic biosensors using dehydrogenases depending on NADH as cofactor.
Faculté des Sciences et des Techniques, Laboratoire d'Analyse Isotopique et Electrochimique de Métabolismes, UMR CNRS 6006, Université de Nantes, 2 rue de la Houssinière, BP 92208, 44322 Nantes, Cedex 03, France. simona.serban@chimbio.univ-nantes.fr
Simona
S
Serban
Nabil
N
El Murr
D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002244:Carbon / Q000737:chemistry; D020099:Coated Materials, Biocompatible; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D005296:Ferrous Compounds / Q000737:chemistry*; D000075163:Metallocenes; D009243:NAD / Q000032:analysis / Q000737:chemistry*; D009245:NADH Dehydrogenase / Q000032:analysis / Q000737:chemistry*; D009824:Ointments; D010084:Oxidation-Reduction; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017641:Zeolites / Q000737:chemistry*
D020099:Coated Materials, Biocompatible; D005296:Ferrous Compounds; D000075163:Metallocenes; D009824:Ointments; D009243:NAD; D017641:Zeolites; D002244:Carbon; D009245:NADH Dehydrogenase; C004998:ferrocene