Electrochemical quartz crystal microbalance analysis of the oxidation reaction of phenols found in wines at lutetium bisphthalocyanine electrodes

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 ph...

Full description

Saved in:
Bibliographic Details
Published in:Sensors and actuators. B, Chemical Chemical, 2013-08, Vol.185, p.24-31
Main Authors: Gay-Martín, Mónica, Díez-Arévalo, Elena, Rodríguez-Méndez, María Luz, de Saja Sáez, José Antonio
Format: Article
Language:English
Subjects:
adsorption
electrochemistry
electrodes
EQCM
gallic acid
ions
lutetium
Lutetium bisphthalocyanine
oxidation
Phenol
Phthalocyanine
quartz
red wines
Voltammetric sensor
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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.
ISSN:0925-4005
1873-3077
DOI:10.1016/j.snb.2013.04.115