Quartz crystal microbalance immunosensor for the quantification of immunoglobulin G in bovine milk
Quartz crystal microbalance immunosensor for the quantification of immunoglobulin G in bovine milk
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DOI：
10.1016/j.bios.2012.11.010
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发表时间：
2013-04-15
影响因子：
12.6
通讯作者：
Rossi, Claire
中科院分区：
文献类型：
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作者：
Crosson, Cyril;Rossi, Claire
在牛奶质量控制领域，开发精确、灵敏的牛奶分析方法一直是一项具有挑战性的任务。研制了一种用于牛乳和初乳中免疫球蛋白G （IgG）实时定量的压电免疫传感器。该传感表面以兔抗牛IgG为检测分子，偶联在羧甲基右旋糖酐包被的金晶体上。总结合和非特异性结合使用石英晶体微天平耗散（QCM-D）测量。采用Doehlert实验设计优化配体固定、牛奶稀释比、盐度、稀释缓冲液pH等分析条件，以提高检测特异性。对优化后的免疫传感器的性能进行了评价。根据QCM-D反应建立标准曲线，在IgG浓度为2500 ng/mL之前呈线性，检出限为46 ng/mL。每个样品的总测定时间为5分钟，包括再生步骤。组内和组间变异系数分别小于或等于4.7和6.1%。该传感表面在100次分析中是稳定的。该技术成功地应用于牛奶中初乳添加量的检测，最低阈值为0.1%。与现有的定量方法相比，这种新的IgG定量方法对乳制品分析实验室来说是一种成本效益高、节省时间的替代方法。(C) 2012 Elsevier B.V.版权所有
The development of precise and sensitive methods for milk analysis remains a challenging task in the milk quality control field. A piezoelectric immunosensor was developed for the real-time quantification of immunoglobulin G (IgG) in bovine milk and colostrum. The sensing surface was designed with rabbit antibovine IgG as the detecting molecule, coupled onto a carboxymethyl dextran-coated gold crystal. Total binding and non-specific binding were measured using a quartz crystal microbalance with dissipation (QCM-D). Conditions of analysis, including ligand immobilization, dilution ratio of milk, salinity, and pH of the dilution buffer were optimized by Doehlert experimental design in order to enhance the detection specificity. The performances of the optimized immunosensor were evaluated. The standard curve was established from QCM-D responses and was linear until an IgG concentration of 2500 ng/mL, with a detection limit of 46 ng/mL. The total assay time is 5 min per sample, including the regeneration step. The intra- and inter-assay variation coefficients were equal to or below 4.7 and 6.1%, respectively. The sensing surface was stable for 100 analyses. This technique was successfully applied to the detection of colostrum addition in milk, with a minimum threshold of 0.1%. This new IgG quantification method is particularly interesting as a cost-effective and time-saving alternative for the dairy analytical laboratories when compared with the existing quantification methods. (C) 2012 Elsevier B.V. All rights reserved.