百菌清单抗与稀土铕荧光纳米微球通过竞争法供价偶联，合成荧光标记免疫探针，开发了一种现场定量检测百菌清的高敏荧光检测卡，建立了蔬菜水果中百菌清快速定量检测的荧光免疫分析方法。实验筛选了具有高灵敏度和特异性的百菌清抗原抗体，优化了纳米荧光微球与百菌清单抗的标记条件、百菌清抗原在硝酸纤维膜上包被浓度、稀释复溶液配方等条件。研制的荧光免疫层析试纸条，与荧光检测仪配套使用，样品前处理有机溶剂用量少。该研究确定最优实验条件为：抗体0.05 mg/mL，NC膜上百菌清抗原包被质量浓度0.8 mg/mL、pH值7.2的PBS缓冲液（甲醇体积分数8%），并建立标准曲线，方法线性范围为2~100 ng/mL，检出限为0.2 mg/kg，与常用类型农药交叉反应率<1%。在基质限量加标水平下，百菌清的加标回收率为85%~98%，产品批内相对标准偏差为8%~12%，批间精密度11%~17%，加标样品的检测结果与气相色谱法无显著性差异。结果表明该研究建立的高敏荧光分析方法具有速度快、准确性好、特异性强、灵敏度高、绿色环保的特点，适用于蔬菜水果中百菌清的现场快速定量筛查。

The competition method was used to couple a monoclonal antibody against chlorothalonil with the rare earth europium florescent nanospheres to synthesize a fluorescent labeled immune probe. This probe was used with a highly sensitive and rapid lanthanide fluorescent immunochromatography card for the rapid quantification of chlorothalonil in vegetables and fruits through an immunoassay. In this study, a high sensitivity and specificity chlorothalonil antigen was selected, and the labelling conditions of fluorescent nanospheres and chlorothalonicin, coating concentration of flufenicomumab antigen on NC membrane, and proportion of diluted complex solution were optimized. The fluorescence test strip developed in this study was used in conjunction with a fluorescence detector and pre-treatment with low-dosage organic solvent. Herein, the optimum experimental conditions were the concentration of antigen was 0.05 mg/mL, and the concentration of antibody was 0.8 mg/mL, the pH of PBS working buffer was 7.2 (8% methanol). A standard curve was established, and the linear range of the method was 2~100 ng/mL with a detection limit of 0.2 mg/kg. The strip detection of chlorothalonil had strong specificity without any cross reaction observed in certain pesticides. The recovery rate of thiamethoxam was 85~98%, the intra-batch precision was 8%~12%, and the inter-batch precision was 11%~17%. There was no significant difference between the results of actual samples and the national standard method. The rapid time-resolved fluorescence assay developed in this study is fast, accurate, highly sensitive, and green and environmentally friendly, making it suitable for rapid and quantitative screening of chlorothalonil in food of plant origin.

重庆市市场监督管理局科研计划项目（CQSJKJ2022032）；重庆市技术创新与应用发展专项重点项目（CSTB2023TIAD-KPX0066）