A Rapid Immunochromatographic Method Based on Gold Nanoparticles for the Determination of Imidacloprid on Fruits and Vegetables

Imidacloprid (IMP) is toxic and a potential carcinogen that is most widely used as an insecticide for pest control and seed treatment. It is important to produce a rapid and sensitive assay for on-site monitoring. We have developed a novel lateral flow assay (LFA) using a sensitive monoclonal antibody (mAb) for monitoring IMP residues on fruits and vegetables. The 50% inhibition concentration result that was found when using the ELISA method was 0.247 ng mL(−1), with the cut-off limits using the LFA method the result was 10 ng mL(−1) (0.01 M PBS), and in the samples it was 20 ng mL(−1) (with a recovery rate of 96–104.7% for Chinese cabbage, cowpea, apple, and pear samples, respectively). All of the results can be determined within seven minutes. The proposed LFA method is a valid, quick, and stable assay for the on-site detection of IMP in large numbers of samples.