Ag^(+)/Cys介导的核酸探针级联荧光信号免疫检测法测定玉米和大米中黄曲霉毒素B_(1)

A Method for Determination of Aflatoxin B_(1)in Corn and Rice by Using Ag^(+)/Cys Mediated Nucleic Acid Probe Cascade Immunofluorescence Assay

以葡萄糖氧化酶(GOx)催化Ag^(+)/Cys介导的富G-ssDNA/Tb^(3+)核酸探针体系引发荧光强度变化为方法学基础,开发了一种新型ELISA双重级联荧光信号放大系统,对葡萄糖氧化酶具有高的灵敏度响应(低至0.05μg/mLGOx)。将此体系与对GOx负载的纳米微球为信号探针的磁分离免疫体系相结合,建立了一种用于食品中AFB_(1)的高灵敏的双重级联信号放大的荧光免疫检测方法。该方法对AFB_(1)的检出限为0.05 ng/mL,在加标的玉米和大米样品中,添加回收实验结果表明,AFB_(1)的回收率在85.09%~105.2%之间,变异系数(CV)值为6.8%~15.7%。

Based on the fluorescence intensity changes of Glucose Oxidase(GOx)catalyzed Ag^(+)/Cys mediated G-rich ssDNA/Tb^(3+)nucleic acid probe,a novel double cascade fluorescence signal amplification system was developed.The fluorescence system had a high sensitivity response to Gox(as low as 0.05μg/mlGOx).This system was combined with magnetic separation immune system to establish a high-sensitivity double cascade signal amplification fluorescence immunoassay method for detection AFB_(1)in foods.The detection limit of this method for AFB_(1)was 0.05 ng/mL.The results of the addition recovery experiment indicated that the recovery rate of AFB_(1)was 85.09%~105.2%,with the coefficient of variation(CV)was 6.8%~15.7%.