Immunosensor for okadaic acid using quartz crystal microbalance
Immunosensor for okadaic acid using quartz crystal microbalance
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DOI：
10.1016/s0003-2670(02)00922-4
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发表时间：
2002-10
影响因子：
6.2
通讯作者：
A. Tang;M. Pravda;G. Guilbault;S. Piletsky;A. Turner
中科院分区：
文献类型：
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作者：
A. Tang;M. Pravda;G. Guilbault;S. Piletsky;A. Turner
建立了一种用于测定冈田酸（OA）的石英晶体微天平（QCM）免疫传感器，并在标准溶液中进行了优化。研究了蛋白质A、蛋白质G和戊二醛交联聚乙烯亚胺（PEI）偶联技术对冈田酸的测定，结果表明，PEI偶联法测定冈田酸效果良好。采用PEI偶联法，研究了GA活化PEI在晶体表面的最佳孵育时间、OA-牛血清白蛋白（BSA）偶联物的稀释倍数和抗体用量对晶体频率的影响。对OA与牛血清白蛋白的不同摩尔比（4：1、14：1、30：1）进行了检测，使用ELISA和QCM的结果表明，14：1的比例略优于其他两种。交联复合物与金表面的强附着导致38天的优异储存寿命。但传感器的检出限（1.9μg/ml）和灵敏度不令人满意。通过掺入抗体-BSA水凝胶获得了装置性能的显著改善。初步结果表明，可检测分析物的最小量和设备的灵敏度分别提高了524倍和80倍。
An immunosensor for the determination of okadaic acid (OA) using a quartz crystal microbalance (QCM) was developed and optimised in standard solutions. Several coupling techniques, protein A, protein G and polyethylenimine (PEI) with glutaraldehyde (GA) cross-linking, were investigated for the determination of okadaic acid and a very good result was obtained with PEI coupling. With the PEI coupling method, the optimisation of incubation time for the activation of PEI on the crystal surface using GA, the effect of the dilution factor of OA–bovine serum albumin (BSA) conjugate and the amount of antibody on crystal frequency were studied. Different molar ratios (4:1, 14:1, 30:1) of OA to bovine serum albumin for the conjugation were examined and the results using ELISA and a QCM showed that a ratio of 14:1 was slightly better than the other two. The strong attachment of the cross-linked complex to the gold surface resulted in an excellent storage lifetime of 38 days. However, the detection limit (1.9μg/ml) and the sensitivity of the sensor were not satisfactory. Significant improvement of the performance of the device was obtained by incorporating an antibody–BSA hydrogel. Initial results showed that the minimum amount of analyte detectable and the sensitivity of the device were improved by 524- and 80-fold, respectively.