Electrochemical investigations of the reaction mechanism and kinetics between NADH and riboflavin immobilised on amorphous zirconium phosphate

dc.creatorKubota, LT
dc.creatorGorton, L
dc.date1999
dc.dateSEP
dc.date2014-12-02T16:29:29Z
dc.date2015-11-26T16:39:28Z
dc.date2014-12-02T16:29:29Z
dc.date2015-11-26T16:39:28Z
dc.date.accessioned2018-03-28T23:23:06Z
dc.date.available2018-03-28T23:23:06Z
dc.identifierJournal Of Solid State Electrochemistry. Springer Verlag, v. 3, n. 41858, n. 370, n. 379, 1999.
dc.identifier1432-8488
dc.identifierWOS:000082855500002
dc.identifier10.1007/s100080050169
dc.identifierhttp://www.repositorio.unicamp.br/jspui/handle/REPOSIP/65175
dc.identifierhttp://www.repositorio.unicamp.br/handle/REPOSIP/65175
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/65175
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1272487
dc.descriptionElectrochemical investigations of the reaction mechanism and kinetics between riboflavin immobilised on zirconium phosphate (ZPRib) in carbon paste and NADH showed results yielding reliable information about aspects on the mechanism of the electron transfer reaction between the flavin and NADH. The formal potential (E-o') of the adsorbed riboflavin was -220 mV versus SCE at pH 7.0. A shift about 250 mV towards a more positive potential compared with its value in solution was assigned to the interaction between the basic nitrogen of riboflavin and the acid groups of ZP. The invariance of the E-o' with the pH of the contacting solution and the effect of different buffer constituents were attributed to the protection effect of ZP over the riboflavin. The electrocatalytic oxidation of NADH at the electrode was investigated using cyclic voltammetry and rotating disk electrode methodology using a potential of -50mV versus SCE. The heterogeneous electron transfer rate constant, k(obs), was 816 M-1 s(-1) and the Michaelis-Menten constant, K-M, was 1.8 mM (confirming a charge transfer complex intermediate in the reaction) for an electrode with a riboflavin coverage of 6.8 x 10(-10) mol cm(-2). This drastic increase in the reaction rate between NADH and the immobilised riboflavin was assigned to the shirt of the E-o'. A surprising effect with addition of calcium or magnesium. ion to the solution was also observed. The E-o' was shifted to -150 mV versus SCE and the reaction rate for NADH oxidation increased drastically.
dc.description3
dc.description41858
dc.description370
dc.description379
dc.languageen
dc.publisherSpringer Verlag
dc.publisherNew York
dc.publisherEUA
dc.relationJournal Of Solid State Electrochemistry
dc.relationJ. Solid State Electrochem.
dc.rightsfechado
dc.rightshttp://www.springer.com/open+access/authors+rights?SGWID=0-176704-12-683201-0
dc.sourceWeb of Science
dc.subjectriboflavin
dc.subjectNADH
dc.subjectzirconium phosphate
dc.subjectchemically modified carbon paste electrode
dc.subjectChemically Modified Electrodes
dc.subjectDihydronicotinamide Adenine-dinucleotide
dc.subjectReduced Nicotinamide Coenzymes
dc.subjectPotential Sweep Voltammetry
dc.subjectElectrocatalytic Oxidation
dc.subjectAmperometric Biosensors
dc.subjectGraphite-electrodes
dc.subjectGlucose-oxidase
dc.subjectFlavin Analogs
dc.subjectCatalytic-oxidation
dc.titleElectrochemical investigations of the reaction mechanism and kinetics between NADH and riboflavin immobilised on amorphous zirconium phosphate
dc.typeArtículos de revistas


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