Mediator-modified electrodes for catalytic NADH oxidation: high rate constants at interesting overpotentials.
Carbon paste electrodes were modified with a nitrofluorenone derivative, 2,4,7-trinitro-9-fluorenone, adsorbed on zirconium phosphate (ZP). After electrochemical reduction of the fluorenone derivative, it turns into a very efficient mediator for electrocatalytic NADH oxidation, with a formal potential of about +250 mV vs. Ag/AgCl. The electrochemistry and the electrocatalytic properties of the mediator were investigated with cyclic voltammetry and rotating disk electrode methodology. The second order rate constant with NADH was evaluated and found to be higher than 10(6) M(-1) s(-1), thus approaching true diffusion controlled currents for NADH oxidation.
Munteanu
F D
FD
Department of Analytical Chemistry, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden.
Mano
N
N
Kuhn
A
A
Gorton
L
L
D002244:Carbon; D002384:Catalysis; D004566:Electrodes; D009243:NAD / Q000737:chemistry*; D010084:Oxidation-Reduction
D009243:NAD; D002244:Carbon