Development of immunoassay based on rational hapten design for sensitive detection of pendimethalin in environment

Pendimethalin (PND) is one of the most widely used selective herbicides, but it is considered a potential human carcinogen and persistent bioaccumulative toxic chemical. Herein, five haptens with carboxylic groups were synthesized based on rational design and used to immunize mice, respectively. Then the antibodies obtained were evaluated systematically, and an indirect competitive ELISA (ic-ELISA) was developed based on an anti-PND monoclonal antibody. The 50% inhibition concentration and limit of detection of ic-ELISA were 0.53 ng/mL and 0.07 ng/mL, respectively. The cross-reactivities of ic-ELISA for the analogs of PND were ≤ 1.1%. The average recoveries of PND ranged from 79.5% to 107.4% in spiked samples. A good correlation was achieved between the ic-ELISA results and UPLC-MS/MS results in the analysis of blind samples. Thus, this assay provides a rapid and accurate tool for the determination of PND in the agro-products and agricultural producing environment.