Detecting clothianidin residues in environmental and agricultural samples using rapid, sensitive enzyme-linked immunosorbent assay and gold immunochromatographic assay.

Two rapid, sensitive immunoassays based on monoclonal antibody for detecting clothianidin were developed and applied in agricultural samples: a quantitative enzyme-linked immunosorbent assay (ELISA) and a semiquantitative gold immunochromatographic assay (GICA). Under optimal conditions, the half-maximal inhibition concentration (IC50) and the limit of detection (LOD, IC10) of clothianidin were 25.6 and 3.8 ng mL(-1) for ELISA. GICA using colloidal gold-MAb probe had a visual detection limit of 8 ng mL(-1), and the results can be judged by the naked eye within 10 min. The cross-reactivities of the immunoassays with its analogues were negligible except for that with dinotefuran. For the spiked agricultural samples, recoveries of 78.0 to 114.5% with relative standard deviations (RSDs) of 3.2 to 12.8% were achieved for ELISA and further evaluated by GICA. Furthermore, the results of ELISA and GICA for the authentic samples correlated well with those obtained by HPLC. Overall, the proposed ELISA and GICA are satisfactory for rapid, sensitive, and quantitative/semiquantitative detection of clothianidin residues in agricultural samples.