Electrochemical quartz crystal microbalance analysis of the oxidation reaction of phenols found in wines at lutetium bisphthalocyanine electrodes
Autor: | Maria Luz Rodriguez-Mendez, Mónica Gay-Martín, Elena Díez-Arévalo, Jose Antonio De Saja Saez |
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Rok vydání: | 2013 |
Předmět: |
Inorganic chemistry
Metals and Alloys Quartz crystal microbalance Condensed Matter Physics Electrochemistry Redox Surfaces Coatings and Films Electronic Optical and Magnetic Materials chemistry.chemical_compound Adsorption chemistry Electrode Materials Chemistry Phenols Electrical and Electronic Engineering Cyclic voltammetry Instrumentation Quartz |
Zdroj: | UVaDOC. Repositorio Documental de la Universidad de Valladolid Consejo Superior de Investigaciones Científicas (CSIC) |
ISSN: | 0925-4005 |
Popis: | An electrochemical quartz crystal microbalance (EQCM) was used to investigate the processes associated with the mass changes accompanying the phenol oxidation catalysed by a lutetium bisphthalocyanine (LuPc2) film-modified Pt/quartz electrode. The study focused on the analysis of the oxidation of phenols usually found in wines, including vanillic, ferulic, caffeic and gallic acids dissolved in a hydroalcoholic solution simulating the matrix of a red wine. It has been shown that LuPc2 modified EQCM sensors immersed in hydroalcoholic solution exhibit significant mass changes upon electrochemical cycling produced by the ingress/egress of ions necessary to maintain the electroneutrality of the film. Cyclic voltammograms of LuPc2/QCM electrodes immersed in phenols also undergo mass changes associated with the ingress/egress of ions. In addition, progressive mass changes occur upon successive scans. The oxidation/reduction of monophenols produces a progressive increase in the mass, whereas ortho-diphenols show the opposite behaviour. These phenomena have been interpreted in terms of the adsorption of the phenols to the LuPc2 layer and their capability to electropolymerise at the electrode surface. The combination of cyclic voltammetry with electrochemical quartz microbalance (EQCM) has demonstrated its capability to elucidate the complex processes occurring at the surface of voltammetric sensors chemically modified with bisphthalocyanines. 2022-07-7 2022-07-07 |
Databáze: | OpenAIRE |
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