Modified electrodes with new phenothiazine derivatives for electrocatyltic oxidation of NADH

Abstract Phenothiazine derivatives containing two linearly condensed phenothiazine moieties, 16H,18H-dibenzo[c,l]-7,9-dithia-16,18-diazapentacene (I), dibenzo[c,l]-16,18-diacetyl-7,9-dithia-16,18-diazapentacene (II) dibenzo[c,l]-16,18-dibenzoyl-7,9-dithia-16,18-diazapentacene (III), and 16H,18H-dibenzo[c,l]-7,9-dithia-16,18-diazapentacene-7,7,9,9-bis-dioxide (IV), strongly adsorb on spectrographic graphite resulting in modified electrodes with electrocatalytic activity for NADH oxidation. From cyclic voltammetry measurements, performed in aqueous buffer solutions at different potential scan rates and pH values, the rate constants of the heterogeneous electron transfer and the transfer coefficients were estimated. The linear dependence between the peak current and the potential scan rate, corroborated with the slope of the formal standard potential versus pH linear regression, pointed out to a quasi-reversible, surface confined redox process involving 1e−/1H+. The electrocatalytical efficiency, evaluated from cyclic voltammetry, and the second order electrocatalytical rate constant (k1), calculated from rotating disk electrode experiments, revealed the same sequence of the activity decrease: III>II>IV>I. Compound III-modified electrodes were characterized by the highest k1 (1.8×103 M−1 s−1, at pH 7.0) as well as by the highest stability, expressed by the lowest rate of the surface coverage depleting under continuous potential cycling.

[1]  W. Schuhmann,et al.  Biocatalysis and electrocatalysis at carbon paste electrodes doped by diaphorase‐methylene green and diaphorase‐meldola blue , 1993 .

[2]  W. Schuhmann,et al.  New amperometric dehydrogenase electrodes based on electrocatalytic NADH‐oxidation at poly (methylene blue)‐modified electrodes , 1994 .

[3]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[4]  Itamar Willner,et al.  Electrical contact of redox enzyme layers associated with electrodes: Routes to amperometric biosensors , 1997 .

[5]  R. Murray,et al.  CHEMICALLY MODIFIED ELECTRODES , 1977 .

[6]  E. Laviron.  General expression of the linear potential sweep voltammogram in the case of diffusionless electrochemical systems , 1979 .

[7]  T. Ogawa,et al.  OXIDATION POTENTIALS AND ABSORPTION SPECTRA OF PHENOTHIAZINE DERIVATIVES. I: BENZOPHENOTHIAZINES AND TRIPHENODITHIAZINE , 1994 .

[8]  Arne Torstensson,et al.  A kinetic study of the reaction between dihydronicotinamide adenine dinucleotide (NADH) and an electrode modified by adsorption of 1,2-benzophenoxazine-7-one , 1985 .

[9]  P. Elving,et al.  Effects of adsorption, electrode material, and operational variables on the oxidation of dihydronicotinamide adenine dinucleotide at carbon electrodes , 1978 .

[10]  P. Elving,et al.  Anodic oxidation of dihydronicotinamide adenine dinucleotide at solid electrodes; mediation by surface species , 1983 .

[11]  Ioanis Katakis,et al.  Catalytic electrooxidation of NADH for dehydrogenase amperometric biosensors , 1997 .

[12]  I. Němec,et al.  Study of the electrochemical oxidation of phenothiazine derivatives in acetonitrile medium: The effect of the structure on the voltammetric behavior , 1980 .

[13]  P. Tuñón,et al.  Amperometric biosensors based on NAD(P)‐dependent dehydrogenase enzymes , 1997 .

[14]  Theodore Kuwana,et al.  Electrocatalysis of dihydronicotinamide adenosine diphosphate with quinones and modified quinone electrodes , 1978 .

[15]  Miss A.O. Penney.  (b) , 1974, The New Yale Book of Quotations.

[16]  H. Jägfeldt,et al.  Adsorption and electrochemical oxidation behaviour of NADH at a clean platinum electrode , 1980 .

[17]  L. Gorton,et al.  Electrochemical Study of Flavins, Phenazines, Phenoxazines and Phenothiazines Immobilized on Zirconium Phosphate , 1999 .

[18]  R. Murray,et al.  Molecular design of electrode surfaces , 1992 .

[19]  George M. Whitesides,et al.  A methanol/dioxygen biofuel cell that uses NAD+-dependent dehydrogenases as catalysts: application of an electro-enzymatic method to regenerate nicotinamide adenine dinucleotide at low overpotentials , 1998 .

[20]  H. Huck.  Electrochemical investigations of mono- and multilayers of phenoxazine dyes on graphite electrodes , 1999 .

[21]  E. Laviron,et al.  General expression of the linear potential sweep voltammogram for a surface redox reaction with interactions between the adsorbed molecules , 1980 .

[22]  I. Němec,et al.  Determination of chlorpromazine and thioridazine by differential pulse voltammetry in acetonitrile medium. , 1986, Talanta.

[23]  L. Gorton,et al.  A comparative study of some 3,7-diaminophenoxazine derivatives and related compounds for electrocatalytic oxidation of NADH , 1990 .

[24]  Allen J. Bard,et al.  Electrochemical Methods: Fundamentals and Applications , 1980 .

[25]  I. Katakis,et al.  Electrocatalytic oxidation of NADH at graphite electrodes modified with osmium phenanthrolinedione , 1999 .

[26]  Björn Persson,et al.  A chemically modified graphite electrode for electrocatalytic oxidation of reduced nicotinamide adenine dinucleotide based on a phenothiazine derivative, 3-β-naphthoyl-toluidine blue O , 1990 .

[27]  Arne Torstensson,et al.  Electrocatalytic oxidation of reduced nicotinamide coenzymes by graphite electrodes modified with an adsorbed phenoxazinium salt, meldola blue , 1984 .