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⁻¹.

在这项研究中，为了提高常规免疫色谱分析（ICA）的灵敏度，同时采用了两种策略，包括使用高灵敏度标记和更改分析格式，以开发ICA的超灵敏格式。在新格式中，使用了抗och曲霉毒素A（OTA）的第一单克隆抗体，没有任何标记，并且使用poly荧光纳米粒子（EuNPs）标记了第二种多克隆抗体。通过将测试条插入包含所有试剂的微管中，只需一步即可完成检测。结果在12分钟内获得，并通过便携式荧光条读取器读取。与传统格式相比，新格式的ICA的显着特征包括：（1）由于应用了两种扩增策略，检测限（LOD）降低了100倍；（2）减少昂贵的单克隆抗体消耗。评价了建立的方法以低至0.4 pg mL的LOD定量测定OTA^-1。