Nile blue adsorbed onto silica gel modified with niobium oxide for electrocatalytic oxidation of NADH

dc.creatorSantos, AD
dc.creatorGorton, L
dc.creatorKubota, LT
dc.date2002
dc.dateAUG 5
dc.date2014-11-15T02:25:12Z
dc.date2015-11-26T16:30:27Z
dc.date2014-11-15T02:25:12Z
dc.date2015-11-26T16:30:27Z
dc.date.accessioned2018-03-28T23:11:31Z
dc.date.available2018-03-28T23:11:31Z
dc.identifierElectrochimica Acta. Pergamon-elsevier Science Ltd, v. 47, n. 20, n. 3351, n. 3360, 2002.
dc.identifier0013-4686
dc.identifierWOS:000177686700013
dc.identifier10.1016/S0013-4686(02)00272-4
dc.identifierhttp://www.repositorio.unicamp.br/jspui/handle/REPOSIP/81975
dc.identifierhttp://www.repositorio.unicamp.br/handle/REPOSIP/81975
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/81975
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1269964
dc.descriptionA study of modified carbon paste electrode employing Nile blue (NB) adsorbed on silica gel modified with niobium oxide (SN) for electrocatalytic oxidation of reduced nicotinamide adenine dinucleotide (NADH) is described. The adsorbed organic dye on SN was used to prepare a modified carbon paste electrode to investigate its electrochemical properties. The formal potential (E-o') of the adsorbed NB (-230 mV vs. saturated calomel electrode, SCE) showed a shift of 70 mV towards a more positive potential value, compared to NB dissolved in aqueous solution. In solutions with pH between 6.0 and 8.0 did stability and E-o' remained almost constant. However, for a solution pH lower than 6.0 the E-o' was affected by the acidity of the contacting solution, shifting the E-o' towards more positive values. For the solution pHs between 6.0 and 8.0 the electrocatalytic activity remained almost constant. A linear response range for NADH between 1.0 x 10(-5) and 5.2 x 10(-4) mol 1-1, at pH 7.0, was observed for the electrode, with an applied potential of -200 mV versus SCE. The formation of an intermediate charge transfer (CT) complex was proposed to the CT reaction between NADH and adsorbed NB. The heterogeneous electron transfer rate, k(obs), was 1400 M-1 s(-1) and the apparent Michaelis-Menten constant, was 0.21 mM at pH 7.0 evaluated from rotating disk electrode (RDE) experiments with an electrode coverage of about 5.2 x 10(-9) mol cm(-2). The increase in the reaction rate between NADH and the immobilized NB compared to those obtained with dissolved NB was assigned to the shift of the E-o' towards more positive values. (C) 2002 Elsevier Science Ltd. All rights reserved.
dc.description47
dc.description20
dc.description3351
dc.description3360
dc.languageen
dc.publisherPergamon-elsevier Science Ltd
dc.publisherOxford
dc.publisherInglaterra
dc.relationElectrochimica Acta
dc.relationElectrochim. Acta
dc.rightsfechado
dc.rightshttp://www.elsevier.com/about/open-access/open-access-policies/article-posting-policy
dc.sourceWeb of Science
dc.subjectNADH
dc.subjectmodified electrode
dc.subjectniobium oxide
dc.subjectNile blue
dc.subjectelectrocatalysis
dc.subjectReduced Nicotinamide Coenzymes
dc.subjectChemically Modified Electrodes
dc.subjectCarbon-paste Electrodes
dc.subjectZirconium-phosphate
dc.subjectAdenine-dinucleotide
dc.subjectTitanium Phosphate
dc.subjectModified Graphite
dc.subjectMeldolas-blue
dc.subjectSurface
dc.subjectDerivatives
dc.titleNile blue adsorbed onto silica gel modified with niobium oxide for electrocatalytic oxidation of NADH
dc.typeArtículos de revistas


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