Electrochemical magnetic beads-based immunosensing platform for the determination of α-lactalbumin in milk. (15th December 2016)

• Record Type: Journal Article
• Authors: Ruiz-Valdepeñas Montiel, Víctor; Campuzano, Susana; Torrente-Rodríguez, Rebeca M.; Reviejo, A. Julio; Pingarrón, José M.
• Is Part Of: Food chemistry. Volume 213(2016)
• Page Start: 595
• Page End: 601
• Publication Date: 2016-12-15
• Subjects: α-Lactalbumin -- Amperometric immunosensors -- Magnetic beads -- Milk -- Infant formulas; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2016.07.004
• Languages: English
• ISSNs: 0308-8146

Abstract

Graphical abstract: Highlights: First amperometric MBs-based immunosensor for α-LA with excellent sensitivity (LOD 11.0 pg mL −1 ) and selectivity. Determination of α-LA in different milk samples and infant formulas. Good correlation against results provided by a commercial ELISA spectrophotometric kit. Powerful analytical tool for food safety and consumer protection. 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)/H2 O2 system. The α-LA immunosensor exhibited a wide linear range (37.0–5000 pg/ml), a low limit of detection (LOD, 11.0 pg/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.