Electrografting of N',N'-dimethylphenothiazin-5-ium-3,7-diamine (Azure A) diazonium salt forming electrocatalytic organic films on gold or graphene oxide gold hybrid electrodes

Electroactive films containing redox active phenothiazine moieties are covalently bound onto gold and graphene oxide gold hybrid electrodes, using reductive redox grafting of N',N'-dimethylphenothiazin-5-ium-3,7-diamine (Azure A) diazonium salt. The grafting procedure is based on continuou...

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Detalles Bibliográficos
Autores: Gómez-Anquela, C., Abad, Jose M., Marín, A. García, Pariente Alonso, Félix, Piqueras, J., Revenga Parra, Mónica, Pau Vizcaíno, José Luis
Tipo de recurso: artículo
Fecha de publicación:2014
País:España
Institución:Universidad Autónoma de Madrid
Repositorio:Biblos-e Archivo. Repositorio Institucional de la UAM
Idioma:inglés
OAI Identifier:oai:repositorio.uam.es:10486/717698
Acceso en línea:http://hdl.handle.net/10486/717698
https://dx.doi.org/10.1016/j.electacta.2013.11.021
Access Level:acceso abierto
Palabra clave:Aryldiazonium salts
conductive polymer
electrografting
hybrid electrodes
NADH oxidation
redox mediator
Física
Química
Descripción
Sumario:Electroactive films containing redox active phenothiazine moieties are covalently bound onto gold and graphene oxide gold hybrid electrodes, using reductive redox grafting of N',N'-dimethylphenothiazin-5-ium-3,7-diamine (Azure A) diazonium salt. The grafting procedure is based on continuous voltammetric potential sweep of solutions containing the phenothiazine diazonium salt previously generated in situ. Control of the film thickness, electroactivity and stability can easily be exerted through appropriate choice of the concentration and number of potential scans performed. Cyclic Voltammetry, Electrochemical Quartz Crystal Microbalance (EQCM) and Spectroscopic Ellipsometry are used to characterize the growth process as well as the viscoelastic properties of the resulting stable electrografted films. The electron transfer reactions through the films are mediated by the presence of the Azure A redox moieties, which show a quasi-reversible electrochemical response and exhibit a potent electrocatalytic effect toward the oxidation of NADH. This electrocatalytic model has been used to compare the properties of Azure A electrografted films generated on gold electrodes with those obtained on hybrid electrodes composed by graphene oxide modified gold electrodes