School of Bioscience and Biotechnology, Tokyo University of Technology, Katayanagi Institute, Tokyo, Japan.
Biosens Bioelectron. 2010 Feb 15;25(6):1395-401. doi: 10.1016/j.bios.2009.10.039. Epub 2009 Oct 30.
Episodes of shellfish contamination with okadaic acid (OA) are a human health threat that is causing increasing concern. As a way to overcome the shortcomings involved in the reference methods of analysis set by legislations, alternative procedures are envisaged. This paper describes the development of different immunosensors for the analysis of OA, focusing on the comparison of their sensitivity, precision, ease of use and sample matrix effects. Initially, a surface plasmon resonance (SPR)-based immunosensor was developed, which enabled the quantification of the toxin in mussel samples at concentrations in the range of the 160 microg kg(-1) European regulatory limit with good percentages of recovery. Nevertheless, calibration curves with spiked mussel samples showed that matrix effects could not be neglected. Alternatively, a flow-immunosensing system based on kinetic exclusion measurements was developed achieving the theoretical lowest limit of detection enabled by the affinity of the anti-OA antibody (IC(70)=0.03 microg L(-1) in the assay solution). This highly sensitive automated system allows rapid and reliable OA quantification, with no significant matrix effects for the analysis of spiked mussel and scallop samples. Performance features such as high sensitivity and precision, low limits of detection and simplicity of the analysis protocol, shows the biosensing-systems based on kinetic exclusion measurements for toxin detection in shellfish samples as highly performing tools for rapid and continuous screening.
贝类中麻痹性贝类毒素（OA）污染事件对人类健康构成了威胁，引起了越来越多的关注。为了克服法规规定的分析参考方法存在的缺陷，人们设想了替代方法。本文介绍了用于分析 OA 的不同免疫传感器的开发，重点比较了它们的灵敏度、精密度、易用性和样品基质效应。最初，开发了一种基于表面等离子体共振（SPR）的免疫传感器，该传感器能够在贝类样品中定量检测毒素，浓度范围在 160μgkg-1的欧洲监管限制范围内，回收率良好。然而，用加标贻贝样品进行的校准曲线表明，基质效应不容忽视。另一方面，开发了一种基于动力学排除测量的流动免疫传感系统，实现了抗 OA 抗体亲和力允许的理论最低检测限（在测定溶液中为 0.03μg L-1）。该高灵敏度自动系统允许快速可靠地定量 OA，对加标贻贝和扇贝样品的分析没有明显的基质效应。基于动力学排除测量的生物传感系统具有灵敏度和精密度高、检测限低以及分析方案简单等特点，可作为贝类样品中毒素检测的高性能工具，用于快速连续筛查。
