TY - JOUR
T1 - Gold electrodes modified with 16H, 18H-dibenzo[c,l]-7,9-dithia-16,18-diazapentacene for electrocatalytic oxidation of NADH
AU - Rosca, V.
AU - Muresan, L.
AU - Popescu, I.C.
AU - Cristea, C.
AU - Silberg, I.A.
PY - 2001
Y1 - 2001
N2 - 16H,18H-Dibenzo[c,l]-7,9-dithia-16,18-diazapentacene (DDDP), a new phenothiazine derivative containing two linearly condensed phenothiazine rings, strongly adsorbs on polyoriented gold resulting in a modified electrode with electrocatalytic activity for ß-nicotinamide adenine dinucleotide (NADH) oxidation. Cyclic voltammetry (CV) measurements, performed in aqueous buffer solutions at different pH values, allowed to: (i) estimate the standard heterogeneous rate constants (kS˜1 s-1, at pH 7.0) in the pH range between 4 and 8; (ii) demonstrate the electrocatalytic activity of the investigated compound for NADH oxidation. The second-order electrocatalytic rate constant k1 was evaluated from the rotating disk electrode (RDE) technique (k1,[NADH]=0=5.0×103 M-1 s-1, at pH 7.0). The electrochemical behavior and electrocatalytic activity of DDDP are markedly influenced by the intramolecular interaction between the two conjugate phenothiazine rings. The electrocatalytic activity of DDDP (1e-, 1H+ acceptor) was assigned to its ability to extract rapidly from NADH the first electron and the proton.
AB - 16H,18H-Dibenzo[c,l]-7,9-dithia-16,18-diazapentacene (DDDP), a new phenothiazine derivative containing two linearly condensed phenothiazine rings, strongly adsorbs on polyoriented gold resulting in a modified electrode with electrocatalytic activity for ß-nicotinamide adenine dinucleotide (NADH) oxidation. Cyclic voltammetry (CV) measurements, performed in aqueous buffer solutions at different pH values, allowed to: (i) estimate the standard heterogeneous rate constants (kS˜1 s-1, at pH 7.0) in the pH range between 4 and 8; (ii) demonstrate the electrocatalytic activity of the investigated compound for NADH oxidation. The second-order electrocatalytic rate constant k1 was evaluated from the rotating disk electrode (RDE) technique (k1,[NADH]=0=5.0×103 M-1 s-1, at pH 7.0). The electrochemical behavior and electrocatalytic activity of DDDP are markedly influenced by the intramolecular interaction between the two conjugate phenothiazine rings. The electrocatalytic activity of DDDP (1e-, 1H+ acceptor) was assigned to its ability to extract rapidly from NADH the first electron and the proton.
U2 - 10.1016/S1388-2481(01)00197-7
DO - 10.1016/S1388-2481(01)00197-7
M3 - Article
SN - 1388-2481
VL - 3
SP - 439
EP - 445
JO - Electrochemistry Communications
JF - Electrochemistry Communications
IS - 8
ER -