Immunoassay for the detection of cyproconazole in foods: From hapten synthesis to the establishment of a gold immunochromatographic assay

Abstract

Cyproconazole (CPZ) is extensively used in agricultural production. However, its overuse can lead to high residue problems in crops. Existing detection methods are still dominated by instrumental methods and the development of rapid, sensitive field detection remains a challenge. In this study, we designed a novel hapten synthetic pathway and prepared a monoclonal antibody (mAb) that could specifically recognize CPZ with high sensitivity (half inhibition rate was 0.27 ng/mL). From this, a gold immunochromatographic assay (GICA) for the detection of CPZ was established by combining the mAb with gold nanoparticles, with limits of detection in rice, tomatoes and grapes of 0.02 mg/kg, 0.01 mg/kg and 0.05 mg/kg, respectively. The spiked recoveries ranged from 86.5 % to 115.1 %, and the results showed that the GICA was not significantly different from detection using LC-MS/MS. Therefore, we have successfully developed a GICA method for the reliable in situ, rapid and sensitive detection of CPZ.