Departamento de Química Analítica, Facultad de CC. Químicas, Universidad Complutense de Madrid, E-28040 Madrid, Spain.
Food Chem. 2016 Dec 15;213:595-601. doi: 10.1016/j.foodchem.2016.07.004. Epub 2016 Jul 5.
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.
α-乳白蛋白（α-LA）是牛奶中的一种乳清蛋白，已被确定为过敏原。在这项工作中，我们首次提出了一种基于磁性珠（MBs）的非常灵敏的免疫传感器，用于测定α-LA。夹心构型涉及选择性捕获和辣根过氧化物酶标记的检测抗体，该抗体在一次性丝网印刷碳电极表面上通过磁场捕获，用于使用对苯二酚（HQ）/H2O2 系统进行安培检测。α-LA 免疫传感器表现出宽线性范围（37.0-5000pg/ml）、低检测限（LOD，11.0pg/ml）和对其他非目标蛋白质的显著选择性。基于 MBs 的免疫传感平台成功地用于测定几种牛奶（生牛奶和 UHT 牛奶以及人乳）和婴儿配方中的α-LA。结果与使用商业 ELISA 方法获得的结果相符，从而证实了这种独特方法的分析优点。
