胶体金免疫层析法快速检测金银花中的马拉硫磷

Rapid determination of malathion in Lonicera japonica by colloidal gold immunochromatography

中文关键词:  马拉硫磷  金银花  胶体金免疫层析法（GICA）

英文关键词:malathion  Lonicera japonica  colloidal gold immunochromatography

中文摘要:

      目的 建立了一种通过胶体金免疫层析技术快速测定金银花中马拉硫磷药物残留的方法。方法 金银花中残留的马拉硫磷可与胶体金标记的单克隆抗体结合, 抑制抗体和硝酸纤维素膜(T线)上的抗原结合, 从而引起T线颜色变化。本研究比较分析了不同pH、抗体添加量、抗原包被量、冻干保护剂种类、Tween 20添加量等因素对检测结果的影响。结果 通过研究发现马拉硫磷单克隆抗体(malathion monoclonal antibody, mAb)和羊抗鼠免疫球蛋白(goat anti-mouse immunoglobulin, IgG)金标抗体制备的最适pH为9.0, Tween 20为最适宜添加量为50 μL, 金标抗体的最适宜冻干保护剂为1.0 g蔗糖+0.5 g 牛血清白蛋白+0.5 g甘露醇, 优化后的方法对于银花中的马拉硫磷的检出限为50 μg/kg, 同时该方法对于马拉硫磷有很好的特异性(200~1000 μg/kg的水胺硫磷、丙溴磷、甲拌磷和倍硫磷均不能产生反应), 使用阴性样品和阳性样品进行方法验证发现该方法假阳性率为1.0%, 假阴性率为0.5%, 做到了现有标准方法的检测结果一致。根据该方法制作的检测卡在室温、密封、干燥环境条件下可以保存1年。结论 本研究所建立的方法操作简便, 特异性强, 灵敏度和准确度高, 检测时间短且稳定性好, 可用于金银花大量样品的马拉硫磷残留的快速检测。

英文摘要:

      Objective To establish a method for the rapid determination of malathion drug residues in Lonicera japonica by colloidal gold immunochromatography. Methods The residual malathion in honeysuckle can bind to the colloidal gold-labeled monoclonal antibody, inhibiting the binding of the antibody to the antigen on the nitrocellulose membrane (T line) and resulting in a color change on the T line, this study analyzed the effects of various factors, such as pH, antibody addition amount, antigen coating amount, type of freeze-drying protective agent, and Tween 20 addition amount on the test results. Results The optimal conditions determined were as follows: The optimal pH for preparing the malathion monoclonal antibody (mAb) and goat anti-mouse immunoglobulin (lgG) gold-labeled antibody was 9.0; the optimal amount of Tween 20 added was 50 μL; and the optimal lyophilization protectant for the gold-labeled antibody was a mixture of 1.0 g sucrose, 0.5 g bovine serum albumin and 0.5 g mannitol. The optimized method achieved a limit of detection was 50 μg/kg for malathion in Lonicera japonica. Furthermore, the method exhibited high specificity for malathion; no cross-reactivity was observed with isocarbophos, profenofos, phoxim or fenthion at concentrations ranging from 200 to 1000 μg/kg. Method validation using negative and positive samples showed a false-positive rate of 1% and a false-negative rate of 0.5%, achieving consistency with the results from existing standard methods. The test strips produced based on this method could be stored for one year at room temperature under sealed and dry conditions. Conclusion The method established in this study is simple to operate, highly specific, sensitive and accurate. It requires a short detection time and demonstrates good stability, making it suitable for the rapid screening of malathion residues in large batches of Lonicera japonica samples.