金纳米花免疫层析试纸条检测果蔬中的苯醚甲环唑

Detection of difenoconazole in fruits and vegetables by gold nanoflowers immunochromatographic strip

目的以粒径为65 nm的花状胶体金(gold nanoflowers,AuNFs)为探针,构建一种可检测果蔬中苯醚甲环唑(difenoconazole,DIFE)的新型免疫层析方法。方法使用球状胶体金(gold nanospheres,AuNSs)、AuNFs分别与DIFE单克隆抗体制备胶体金免疫探针,对反应体系进行优化,开发出适用于DIFE离子的胶体金免疫层析(gold immunochromatographic assay,GICA)试剂条。结果以AuNFs为探针制备的试纸条检出限为0.050 mg/kg,比以AuNSs为探针制备的试纸条检测灵敏度提高10倍,检测时间为15 min,与其他三唑类农药无交叉反应,假阴性率为0,假阳性率为3.75%,可特异性检测果蔬中的DIFE残留。结论以AuNFs为探针制备的试纸条准确性良好、特异性强,可在多种食物基质中实现对果蔬DIFE的快速检测。

Objective To construct a new immunochromatographic method for detecting difenoconazole(DIFE)in fruits and vegetables,with gold nanoflowers(AuNFs)with a particle size of 65 nm as a probe.Methods Gold immunochromatographic assay(GICA)was developed by using colloidal gold nanospheres(AuNSs),AuNFs and DIFE monoclonal antibody respectively to prepare colloidal gold immunoprobes,and optimizing the reaction system.Results The limit of detection of the test strip prepared by using AuNFs as probe was 0.050 mg/kg,the sensitivity was 10 times higher than that prepared by using AuNSs as probe.The detection time was 15 min,and there was no cross reaction with other triazole pesticides.The false negative rate was 0 and the false positive rate was 3.75%,which could specifically detect DIFE residues in fruits and vegetables.Conclusion The test strip prepared with AuNFs as probe has good accuracy and strong specificity,which can realize the rapid detection of DIFE in fruits and vegetables in various food substrates.