A novel immunochromatographic assay (ICA) using colored silica nanoparticles (colored SiNPs) as optical directly-detected label was developed for point-of-care detection of clenbuterol (CLE). To our knowledge, this is the first report that using colored SiNPs as nanolabel to develop an ICA. CLE was selected as the model analyte for competitive ICA. The coloration of monodispersed silica nanoparticles (SiNPs) was preceded in water with the presence of aminosilanes and C.I Reactive Violet 5. The purple SiNPs were introduced into a pre-hydrolyzed Stöber system to regrow a silica shell, forming core-shell purple SiNPs. The silica shell prevented dye on SiNPs from leaking. Under appropriate conditions, the core-shell purple SiNPs based ICA was developed to screen for CLE detection by naked eyes at cut-off values of 3 ng/mL, 6 ng/mL and 5 ng/mL in phosphate buffered saline, urine and pork, respectively. The core-shell purple SiNPs based immunoassay system has no cross activity with other nonspecific structural analogues. The results showed that colored SiNPs are promising to be alternative visible labels for the ICA strip.

开发了一种使用有色二氧化硅纳米颗粒（有色SiNPs）作为光学直接检测标记的新型免疫色谱测定法（ICA），用于即时检测克仑特罗（CLE）。据我们所知，这是第一个使用有色SiNPs作为纳米标记来开发ICA的报告。选择CLE作为竞争性ICA的模型分析物。在存在氨基硅烷和CI反应性紫罗兰5的情况下，先在水中对单分散的二氧化硅纳米粒子（SiNPs）进行着色。将紫色的SiNPs引入预水解的Stöber系统中，使二氧化硅壳再生，形成核壳型紫色SiNPs。硅胶壳可防止SiNP上的染料泄漏。在适当的条件下，开发了基于核-壳紫色SiNPs的ICA，用于以3 ng / mL的临界值通过肉眼筛选CLE检测，磷酸盐缓冲盐水，尿液和猪肉中的浓度分别为6 ng / mL和5 ng / mL。基于核-壳紫色SiNPs的免疫分析系统与其他非特异性结构类似物没有交叉活性。结果表明，有色的SiNP有望成为ICA条带的替代可见标签。