摘要
目的:根据荧光共振能量转移(fluorescence resonance energy transfer,FRET)的原理,构建一种基于上转换荧光纳米材料的新型免疫标记荧光猝灭试纸条检测牛奶中的兽药磺胺喹恶啉(sulfaquinoxaline,SQX)残留。方法:通过热分解方法合成上转换纳米荧光材料,通过柠檬酸三钠还原法制备胶体金纳米颗粒。将合成的上转换荧光颗粒固定在试纸条C线上,并将上转换荧光颗粒与SQX包被抗原的混合物固定在T线上,将胶体金标记的SQX单克隆抗体喷涂在金标垫上。滴加样品后,随着样品液的流动,金标抗体会移动到T线处并与SQX包被抗原结合,这种结合会导致抗体上的纳米金颗粒(受体)与T线上的上转换颗粒靠近(供体),从而发生FRET,产生荧光猝灭。在980 nm激发器激发波长下通过目测检测荧光强弱变化,从而实现对SQX的检测。结果:该免疫荧光猝灭试纸条检测SQX的方法检测限为1μg/L,牛奶样品的检测限为8μg/L。整个检测过程不超过15 min。结论:该方法操作简便、灵敏度高、检测时间短、结果易于判断,可以满足牛奶中SQX残留的现场快速检测的要求。
Purpose：A novel fluorescent quenching immune chromatographic strip（FQICS） using upconversion nanoparticles（UCNPs） was developed to detect sulfaquinoxaline（SQX） in milk samples based on the principle of fluorescence resonance energy transfer（FRET）.Methods：UCNPs was prepared using a pyrolytic process,and colloidal gold was prepared using sodium citrate reduction method.Then OVA-UCNPs were distributed to the upper side to form C line.OVA-UCNPs and SQX-OVA coating antigen were added to the lower side of the NC membrane to form the T line.When a negative sample was added to the sample pad,the liquid sample containing colloidal gold-labeled antibody migrated via capillary action toward the end of the strip.When the mixture reached the T line,which was coated with SQX-OVA coating antigen and OVA-UCNPs,the gold-labeled antibody bound to SQX-OVA coating antigen.Since the UCNPs were simultaneously coated at the same location as the SQX-OVA coating antigen,the binding of gold-labeled antibody to SQX-OVA coating antigen could provide a suitable distance between the UCNPs and colloidal gold to cause FRET.Using a 980 nm laser,the test results could be evaluated visually according to fluorescence intensity.Results：The limit of detection（LOD） of this assay for SQX in PBS buffer was 1 μg/L,and the LOD for SQX in milk samples was 8 μg/L.The whole detection process could be completed within 15 min.Conclusion：The FQICS based on UCNPs allowed for simple,sensitive,time-saving,and rapid onsite detection of SQX residues in milk.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2017年第24期218-223,共6页
Food Science
基金
国家国际科技合作专项(2014DFR30350)
天津市科技计划项目(14ZCDGNC00098).
关键词
磺胺喹恶啉
上转换材料
免疫荧光猝灭试纸条
牛奶
sulfaquinoxaline
upconversion nanoparticles
fluorescence quenching immune chromatographic strips
milk
