title: An Electrochemical Quartz Crystal Microbalance Multisensor System Based on Phthalocyanine Nanostructured Films: Discrimination of Musts.
abstract: An array of electrochemical quartz crystal electrodes (EQCM) modified with nanostructured films based on phthalocyanines was developed and used to discriminate musts prepared from different varieties of grapes. Nanostructured films of iron, nickel and copper phthalocyanines were deposited on Pt/quartz crystals through the Layer by Layer technique by alternating layers of the corresponding phthalocyanine and poly-allylamine hydrochloride. Simultaneous electrochemical and mass measurements were used to study the mass changes accompanying the oxidation of electroactive species present in must samples obtained from six Spanish varieties of grapes (Juan García, Prieto Picudo, Mencía Regadío, Cabernet Sauvignon, Garnacha and Tempranillo). The mass and voltammetric outputs were processed using three-way models. Parallel Factor Analysis (PARAFAC) was successfully used to discriminate the must samples according to their variety. Multi-way partial least squares (N-PLS) evidenced the correlations existing between the voltammetric data and the polyphenolic content measured by chemical methods. Similarly, N-PLS showed a correlation between mass outputs and parameters related to the sugar content. These results demonstrated that electronic tongues based on arrays of EQCM sensors can offer advantages over arrays of mass or voltammetric sensors used separately.
authors.affiliation: Department of Inorganic Chemistry, Engineers School, University of Valladolid, Valladolid 47011, Spain. Celiagarciahernandez@gmail.com.
authors.forename: Celia
authors.initials: C
authors.lastname: Garcia-Hernandez
authors.affiliation: Department of Inorganic Chemistry, Engineers School, University of Valladolid, Valladolid 47011, Spain. Crismedina@eii.uva.es.
authors.forename: Cristina
authors.initials: C
authors.lastname: Medina-Plaza
authors.affiliation: Department of Materials Science, Engineers School, University of Valladolid, Valladolid 47011, Spain. crigar@eii.uva.es.
authors.forename: Cristina
authors.initials: C
authors.lastname: Garcia-Cabezon
authors.affiliation: Department of Materials Science, Engineers School, University of Valladolid, Valladolid 47011, Spain. fmp@eii.uva.es.
authors.forename: Fernando
authors.initials: F
authors.lastname: Martin-Pedrosa
authors.affiliation: Department of Electronic Technology, Engineers School, University of Valladolid, Valladolid 47011, Spain. isaval@eii.uva.es.
authors.forename: Isabel
authors.initials: I
authors.lastname: del Valle
authors.affiliation: Department of Condensed Matter Physics, Faculty of Sciences, University of Valladolid, Valladolid 47011, Spain. sajasaez@fmc.uva.es.
authors.forename: Jose
authors.initials: J
authors.lastname: Antonio de Saja
authors.affiliation: Department of Inorganic Chemistry, Engineers School, University of Valladolid, Valladolid 47011, Spain. mluz@eii.uva.es.
authors.forename: Maria Luz
authors.initials: ML
authors.lastname: Rodríguez-Méndez
keywords: EQCM; LbL; electronic tongue; grapes; must; phthalocyanine