Dual-labeled time-resolved fluoroimmunoassay for simultaneous detection of clothianidin and diniconazole in agricultural samples

Europium (Eu 3+ ) and samarium (Sm 3+ ) were used as fluorescent labels to develop a highly sensitive dual-labeled time-resolved fluoroimmunoassay (TRFIA) for detect clothianidin and diniconazole in food samples. Under the optimized assay conditions, 50% inhibition concentration (IC 50 ) and the limit of detection (LOD, IC 10 ) of clothianidin were 5.08 and 0.021   μg/L, and 13.14 and 0.029   μg/L for diniconazole. The cross-reactivities (CRs) were negligible except dinotefuran (9.4%) and uniconazole (4.28%). The recoveries of clothianidin and diniconazole ranged from 79.3% to 108.7% in food samples. The results of TRFIA for the authentic samples were validated by gas chromatography (GC) analyses, and a satisfactory correlations were obtained. These results indicated that the method was an alternative tool for simultaneous detection of clothianidin and diniconazole in food samples.