title: Electrochemical magnetic beads-based immunosensing platform for the determination of α-lactalbumin in milk.
abstract: Alpha-lactalbumin (α-LA) is one of the whey proteins in cows' milk that has been identified as allergenic. In this work, we present, for the first time, a very sensitive magnetic beads (MBs)-based immunosensor for the determination of α-LA. A sandwich configuration involving selective capture and horseradish peroxidase-labeled detector antibodies was implemented on carboxylic acid-modified magnetic beads, captured magnetically under the surface of a disposable screen-printed carbon electrode for amperometric detection using the hydroquinone (HQ)/H2O2 system. The α-LA immunosensor exhibited a wide linear range (37.0-5000pg/ml), a low limit of detection (LOD, 11.0pg/ml) and noteworthy selectivity against other non-target proteins. The MBs-based immunosensing platform was applied successfully for the determination of α-LA in several varieties of milk (raw and UHT cows' milk as well as human milk) and infant formulations. The results were corroborated with those obtained using a commercial ELISA method, thereby substantiating the analytical merits of this unique method.
authors.affiliation: Departamento de Química Analítica, Facultad de CC. Químicas, Universidad Complutense de Madrid, E-28040 Madrid, Spain. Electronic address: victor_lega90@hotmail.com.
authors.forename: Víctor
authors.initials: V
authors.lastname: Ruiz-Valdepeñas Montiel
authors.affiliation: Departamento de Química Analítica, Facultad de CC. Químicas, Universidad Complutense de Madrid, E-28040 Madrid, Spain. Electronic address: susanacr@quim.ucm.es.
authors.forename: Susana
authors.initials: S
authors.lastname: Campuzano
authors.affiliation: Departamento de Química Analítica, Facultad de CC. Químicas, Universidad Complutense de Madrid, E-28040 Madrid, Spain. Electronic address: rebeca.magnolia@gmail.com.
authors.forename: Rebeca M
authors.initials: RM
authors.lastname: Torrente-Rodríguez
authors.affiliation: Departamento de Química Analítica, Facultad de CC. Químicas, Universidad Complutense de Madrid, E-28040 Madrid, Spain. Electronic address: reviejo@quim.ucm.es.
authors.forename: A Julio
authors.initials: AJ
authors.lastname: Reviejo
authors.affiliation: Departamento de Química Analítica, Facultad de CC. Químicas, Universidad Complutense de Madrid, E-28040 Madrid, Spain. Electronic address: pingarro@quim.ucm.es.
authors.forename: José M
authors.initials: JM
authors.lastname: Pingarrón
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D002417:Cattle; D005260:Female; D006801:Humans; D018189:Immunomagnetic Separation / Q000379:methods*; D007768:Lactalbumin / Q000737:chemistry*; D008892:Milk / Q000737:chemistry*
chemical_list: D007768:Lactalbumin
keywords: Amperometric immunosensors; Infant formulas; Magnetic beads; Milk; α-Lactalbumin