小麦面粉中赭曲霉毒素A的CdSe/ ZnS荧光量子点免疫探针检测
Detection of Ochratoxin A in Wheat Flour Using CdSe/ZnS Core/Shell Quantum Dots by Fluoroimmunoassay

构建一种基于荧光量子点免疫探针的小麦面粉中赭曲霉毒素A（OTA）的检测方法。以EDC为活化剂将CdSe/ZnS半导体荧光量子点与OTA单克隆抗体偶联，制备OTA检测探针并评价其检测性能。结果表明：制备的检测探针在3 d保存期内具有良好的稳定性。当OTA质量浓度为0.1~0.9 μg/L时，检测探针的荧光强度与OTA质量浓度呈线性关系，其相关系数为0.996 3，检出限为0.017 7 μg/L。与国标法对照的结果说明，此方法具有可行性。小麦面粉中的加标回收试验结果显示，OTA的回收率为96.0%~102.7%，相对标准偏差不超过4.1%，说明准确性良好。可见，OTA的CdSe/ZnS荧光量子点免疫探针检测方法操作简单、准确度高、结果稳定，有望应用于小麦面粉中OTA的检测。
We developed a method for detection of ochratoxin A(OTA) in wheat flour based on quantum dots by fluoroimmunoassay. The semiconductor fluorescent quantum dots CdSe/ZnS were conjugated with OTA monoclonal antibody using EDC as activating agent.The detection performance of the as-prepared detection probe was evaluated. Results showed that the detection probe was stable within 3 days. When the mass concentration of OTA was in the range of 0.1 to 0.9 μg/L, fluorescence intensity of the detection probe presented a good linear range relationship to the concentration of OTA with a correlation coefficient of 0.996 3, and the detection limit was found to be 0.017 7 μg/L. Evaluation of the feasibility of the method by comparing with the GB detection method of OTA in aqueous solutions,showed that the new method was feasible. Standard addition recovery test of OTA in wheat flour was conducted to evaluate accuracy of the method.The results showed that OTA recoveries ranged from 96.0% to 102.7% and the relative standard deviation did not exceed 4.1%,which indicated that the method had great accuracy and could be applied to OTA detection in wheat flour.