Department of Food Science and Technology, College of Agriculture, Shiraz University, Shiraz 71441-65186, Iran.
Fraunhofer Institute for Process Engineering and Packaging IVV, Freising 85354, Germany.
Food Chem. 2019 Mar 1;275:721-729. doi: 10.1016/j.foodchem.2018.09.112. Epub 2018 Sep 19.
In this study, to enhance the sensitivity of conventional immunochromatographic assay (ICA) two strategies including using a high sensitive label and changing the assay format, were simultaneously applied to develop an ultrasensitive format of ICA. In new format, primary monoclonal antibody against ochratoxin A (OTA) was used without any labeling, and a secondary polycolonal antibody was labeled with europium fluorescent nanoparticles (EuNPs). Detection was performed in a single step by inserting the test strip into a microtube containing all reagents. The results were obtained within 12 min and read by a portable fluorescent strip reader. Salient features of the new format of ICA compared with conventional format include: (1) A 100-fold decrease in limit of detection (LOD) due to application of two amplification strategy; (2) Reduction in expensive monoclonal antibody consumption. The established method was evaluated for the quantitative determination of OTA with LOD as low as 0.4 pg mL.
在这项研究中，为了提高常规免疫层析分析（ICA）的灵敏度，同时应用了两种策略，包括使用高灵敏度的标记物和改变分析形式，从而开发出一种超灵敏的 ICA 分析形式。在新形式中，使用了未经任何标记的针对赭曲霉毒素 A（OTA）的单克隆抗体作为一级抗体，而二级多克隆抗体则用铕荧光纳米颗粒（EuNPs）进行标记。通过将测试条插入含有所有试剂的微管中，可一步完成检测。结果在 12 分钟内获得，并通过便携式荧光条读取器进行读取。与传统形式相比，新的 ICA 形式的显著特点包括：（1）由于应用了两种放大策略，检测限（LOD）降低了 100 倍；（2）减少了昂贵的单克隆抗体的消耗。该方法用于定量测定 OTA，LOD 低至 0.4pgmL。
