摘要:
目的:根据竞争抑制免疫层析原理,构建一种基于量子点标记的免疫层析试纸条用于检测谷物中赭曲霉毒素A(Ochratoxin A,OTA)的残留量。方法:通过活化酯法将羧基功能化的量子点(Quantum dot,QD)与赭曲霉毒素A多克隆抗体(Antibody,Ab)偶联制备量子点抗体偶联物(QD-Ab);通过分别添加不同量的QD-Ab和工作液,优化量子点标记免疫层析试纸条的工作条件;通过商品化试剂盒验证该方法的有效性。结果:当QD与Ab的摩尔比为1:10时,QD-Ab荧光特性最佳;在QD-Ab和工作液添加量分别为1、10 μL时,量子点标记免疫层析试纸条结果最佳;量子点标记免疫层析试纸条的检测限为0.5 μg/L,谷物样品中的检测限为5 μg/kg,整个检测过程不超过10 min;量子点标记免疫层析试纸条特异性良好且具有有效性。结论:该方法操作简便、检测快速、结果准确灵敏,易于判断,可以满足谷物中赭曲霉毒素A残留量现场快速检测的要求。
Abstract:
Objective:A quantum dot-labeled immunochromatographic test strip for the determination of ochratoxin A(OTA)in cereals was developed based on the competitive inhibition principle. Methods:Quantum dot antibody conjugates(QD-Ab)were prepared by coupling an carboxy-functionalized quantum dot(QD)with an ochratoxin A polyclonal antibody(Antibody,Ab)via the activated ester method;Different amounts of QD-Ab and working fluid were used to optimize the working conditions of the quantum dot-labeled immunochromatographic test strip;The effectiveness of the method was verified by a commercial kit. Results:When the molar ratio of QD to Ab was 1:10,the fluorescence characteristics of QD-Ab were the best;when QD-Ab and working fluid were added at 1,10 μL,respectively,the best results of quantum dot-labeled immunochromatographic test strips were obtained;The detection limit of the quantum dot-labeled immunochromatographic test strip in the assay buffer was 0.5 μg/L,and the detection limit of OTA in the cereal sample was 5 μg/kg,the entire detection process could be completed within 10 min;The quantum dot-labeled immunochromatographic test strip had good specificity and effectiveness. Conclusion:This assay is simple,rapid,and sensitivity. It can meet the requirements of on-site rapid detection of ochratoxin A in cereals.
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