Hu Gaoshuang, Sheng Wei, Zhang Yan, Wu Xuening, Wang Shuo
Key Laboratory of Food Nutrition and Safety, Ministry of Education of China, Tianjin University of Science and Technology, Tianjin, 300457, China.
Anal Bioanal Chem. 2015 Nov;407(28):8487-96. doi: 10.1007/s00216-015-8996-4. Epub 2015 Sep 4.
A novel fluorescence immunoassay to detect fluoroquinolones in animal-derived foods was developed for the first time by use of upconversion nanoparticles as signal-probe labels. The bioassay system was established by the use of coating-antigen-modified polystyrene particles as immune-sensing probes for separation and anti-norfloxacin monoclonal antibody conjugated with carboxyl-functionalized NaYF4:Yb,Er upconversion nanoparticles which were prepared via a pyrolysis method and a subsequent ligand exchange process as fluorescent-signal probes (emission intensity recorded at 542 nm with excitation at 980 nm). Under optimized conditions, detection of fluoroquinolones was performed easily. The detection limit of this fluorescence immunoassay for norfloxacin, for example, was 10 pg mL(-1), within a wide linear range of 10 pg mL(-1) to 10 ng mL(-1) (R (2) = 0.9959). For specificity analysis, the data obtained indicate this method could be applied in broad-spectrum detection of fluoroquinolones. The recoveries of norfloxacin-spiked animal-derived foods ranged from 82.37 to 132.22 %, with coefficients of variation of 0.24-25.06 %. The extraction procedure was rapid and simple, especially for milk samples, which could be analyzed directly without any pretreatment. In addition, the results obtained with the method were in good agreement with those obtained with commercial ELISA kits. The fluorescence immunoassay was more sensitive, especially with regard to the detection limit in milk samples (0.01 ng mL(-1) for norfloxacin): it was 50-fold more sensitive than commercial ELISA kits (0.5 ng mL(-1) for norfloxacin). The results show the proposed fluorescence immunoassay was facile, sensitive, and interference free, and is an alternative method for the quantitative detection of fluoroquinolone residues in animal-derived foods.
首次开发了一种利用上转换纳米粒子作为信号探针标记物检测动物源性食品中氟喹诺酮类药物的新型荧光免疫分析方法。通过使用包被抗原修饰的聚苯乙烯颗粒作为免疫传感探针进行分离，并将羧基功能化的NaYF4:Yb,Er上转换纳米粒子（通过热解法和随后的配体交换过程制备）与抗诺氟沙星单克隆抗体偶联作为荧光信号探针（在980 nm激发下，在542 nm处记录发射强度），建立了生物分析系统。在优化条件下，可轻松进行氟喹诺酮类药物的检测。例如，该荧光免疫分析方法对诺氟沙星的检测限为10 pg mL(-1)，线性范围宽，为10 pg mL(-1)至10 ng mL(-1)（R (2) = 0.9959）。特异性分析结果表明，该方法可用于氟喹诺酮类药物的广谱检测。添加诺氟沙星的动物源性食品的回收率为82.37%至132.22%，变异系数为0.24%至25.06%。提取过程快速简单，特别是对于牛奶样品，无需任何预处理即可直接分析。此外，该方法获得的结果与商业ELISA试剂盒获得的结果高度一致。荧光免疫分析更灵敏，特别是在牛奶样品的检测限方面（诺氟沙星为0.01 ng mL(-1)）：比商业ELISA试剂盒（诺氟沙星为0.5 ng mL(-1)）灵敏50倍。结果表明，所提出的荧光免疫分析方法简便、灵敏、无干扰，是定量检测动物源性食品中氟喹诺酮类药物残留的一种替代方法。
