AbstractAn immunochromatographic assay (ICA) is presented that can be applied to simultaneous detection of clenbuterol (CLE) and ractopamine (RAC). It is making use of two red and blue silica nanoparticles (SiNPs) that act as labels for encoding the antibodies. This design permits multiplexed analysis in a single test line and does not require an external source for photoexcitation. Anti-CLE was labeled with red SiNPs, and anti-RAC with blue SiNPs. The capture antigens CLE-BSA and RAC-BSA were placed onto the conjugate pad and the test line of the test strip, respectively. Under bare eye examination, no cross-colored lines or nonspecific bioconjugate adsorption were observed, and the visible limit of detections for CLE (red) and RAC (blue) are 3 and 2 ng‧mL−1, respectively. This design allows for multiplexed detection with reduced device dimensions and costs, and with easy integration and manufacturing. Conceivably, the method may be extended to simultaneous determination of numerous other analytes. Graphic abstractThe principle of qualitative detection strategy of multiplex immunochromatographic assay for clenbuterol (CLE) and ractopamine (RAC) is schematically illustrated. Depending on the type and ratio of organic dyes, the color of colored silica nanoparticle can be tuned from red to purple and even to black (lower right corner).

中文翻译：

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基于二氧化硅纳米颗粒的 2 色免疫色谱法同时测定克伦特罗和莱克多巴胺

摘要提出了一种免疫色谱法 (ICA)，可用于同时检测克仑特罗 (CLE) 和莱克多巴胺 (RAC)。它利用两种红色和蓝色二氧化硅纳米粒子 (SiNP) 作为标记来编码抗体。这种设计允许在单个测试线中进行多重分析，并且不需要外部光激发源。Anti-CLE 用红色 SiNPs 标记，anti-RAC 用蓝色 SiNPs 标记。将捕获抗原 CLE-BSA 和 RAC-BSA 分别放置在结合垫和测试条的测试线上。在裸眼检查下，没有观察到交叉色线或非特异性生物偶联物吸附，CLE（红色）和RAC（蓝色）的可见检测限分别为3和2 ng·mL-1。这种设计允许多路检测，同时减少设备尺寸和成本，并且易于集成和制造。可以想象，该方法可以扩展到同时测定许多其他分析物。图文摘要图解说明了克仑特罗（CLE）和莱克多巴胺（RAC）多重免疫层析法的定性检测策略原理。根据有机染料的类型和比例，有色二氧化硅纳米粒子的颜色可以从红色调至紫色，甚至调至黑色（右下角）。图文摘要图解说明了克仑特罗（CLE）和莱克多巴胺（RAC）多重免疫层析法的定性检测策略原理。根据有机染料的类型和比例，有色二氧化硅纳米粒子的颜色可以从红色调至紫色，甚至调至黑色（右下角）。图文摘要图解说明了克仑特罗（CLE）和莱克多巴胺（RAC）多重免疫层析法的定性检测策略原理。根据有机染料的类型和比例，有色二氧化硅纳米粒子的颜色可以从红色调至紫色，甚至调至黑色（右下角）。