Abstract：
Niclosamide is usually used for the treatment of parasite infections in animals. However, niclosamide and one of its metabolites 2-chloro-4-nitroaniline are mutagenic substances, and their residues in animal-derived foods are potential risks to consumers. As far as we know, there has been no immunoassay or pseudo immunoassay reported to determine niclosamide and its metabolites in animal-derived foods. In this study, a molecularly imprinted microsphere for niclosamide was first synthesized, and a streptavidin-horseradish peroxidase labelled conjugate was also synthesized. The two reagents were used to develop a pseudo enzyme-linked immunosorbent assay on conventional microplates for the determination of niclosamide and its two metabolites (2-chloro-4-nitroaniline and 5-chlorosalicylic acid) in fish. Because biotinylated horseradish peroxidase was used to amplify the signal, the method sensitivities for the three analytes were increased fivefold to 27.5-fold (limits of detection of 0.004-0.03 ng/mL) in comparison with the use of single horseradish peroxidase labelled conjugate (limits of detection of 0.11-0.16 ng/mL). Their recoveries from the standards fortified blank fish samples were in the range of 70.6-95.5%. This is the first study reporting a molecularly imprinted polymer-based pseudo immunoassay for screening of niclosamide and its metabolites in food sample.
摘要：
氯硝柳胺通常用于治疗动物中的寄生虫感染。然而,氯硝柳胺及其代谢产物之一2-氯-4-硝基苯胺是诱变物质，它们在动物源性食品中的残留对消费者来说是潜在的风险。据我们所知,目前还没有关于测定动物源性食品中氯硝柳胺及其代谢产物的免疫测定或假免疫测定的报道。在这项研究中,首先合成了氯硝柳胺的分子印迹微球，还合成了链霉亲和素-辣根过氧化物酶标记的缀合物。这两种试剂用于在常规微孔板上开发假酶联免疫吸附测定，以测定鱼中的氯硝柳胺及其两种代谢物（2-氯-4-硝基苯胺和5-氯水杨酸）。因为生物素化的辣根过氧化物酶被用来放大信号，与使用单个辣根过氧化物酶标记的缀合物（检测限为0.11-0.16ng/mL）相比，对三种分析物的方法灵敏度提高了五倍，达到27.5倍（检测限为0.004-0.03ng/mL）。它们从标准强化的空白鱼样品中的回收率在70.6-95.5％的范围内。这是首次报道基于分子印迹聚合物的假免疫测定法，用于筛选食品样品中的氯硝柳胺及其代谢物。
