Cyclic voltammetry has been successfully used to study the oxidation of nicotinamide adenine dinucleotide (NADH) at single-wall carbon-nanotube-paste (CNTP) electrodes modified with p-methylaminophenolsulfate (p-MAP) and 3,4-dihydroxybenzaldehyde (3,4-DHB). Diffusion-like behaviour was observed for p-MAP-modified electrodes, and a diffusion coefficient of 2.4×10–6 cm2 s–1 was calculated for p-MAP in the paste. The behaviour of 3,4-DHB-modified CNTP electrodes was typical of that of surface-confined mediators. p-MAP electrocatalytic activity was first checked in solution, and a rate constant of 9.2 mol–1 L s–1 was obtained for the reaction between NADH and the mediator. The p-MAP-modified electrode did not have significant electrocatalytic activity for electro-oxidation of NADH, probably because of the formation of a complex between NADH and the confined mediator. In contrast, the 3,4-DHB-modified electrode had very good NADH electrocatalytic activity, with a heterogeneous rate constant of approximately 20×102 mol–1 L s–1.
Electrocatalytic oxidation of NADH at single-wall carbon nanotube-paste electrodes: kinetic considerations for use of a redox mediator in solution and dissolved in the paste / Antiochia, Riccarda; I., Lavagnini; F., Magno. - In: ANALYTICAL AND BIOANALYTICAL CHEMISTRY. - ISSN 1618-2642. - STAMPA. - 381:(2005), pp. 1355-1361. [10.1007/s00216-005-3079-6]
Electrocatalytic oxidation of NADH at single-wall carbon nanotube-paste electrodes: kinetic considerations for use of a redox mediator in solution and dissolved in the paste
ANTIOCHIA, RICCARDA;
2005
Abstract
Cyclic voltammetry has been successfully used to study the oxidation of nicotinamide adenine dinucleotide (NADH) at single-wall carbon-nanotube-paste (CNTP) electrodes modified with p-methylaminophenolsulfate (p-MAP) and 3,4-dihydroxybenzaldehyde (3,4-DHB). Diffusion-like behaviour was observed for p-MAP-modified electrodes, and a diffusion coefficient of 2.4×10–6 cm2 s–1 was calculated for p-MAP in the paste. The behaviour of 3,4-DHB-modified CNTP electrodes was typical of that of surface-confined mediators. p-MAP electrocatalytic activity was first checked in solution, and a rate constant of 9.2 mol–1 L s–1 was obtained for the reaction between NADH and the mediator. The p-MAP-modified electrode did not have significant electrocatalytic activity for electro-oxidation of NADH, probably because of the formation of a complex between NADH and the confined mediator. In contrast, the 3,4-DHB-modified electrode had very good NADH electrocatalytic activity, with a heterogeneous rate constant of approximately 20×102 mol–1 L s–1.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
