Rapid and sensitive determination of difenoconazole in cucumber and pear samples using an immunochromatographic assay

Difenoconazole is triazole fungicide, widely used to prevent the growth and reproduction of fungi and to control fungal diseases in fruits and vegetables. In this work, we prepared a hapten of difenoconazole and produced a highly-sensitive anti difenoconazole-monoclonal antibody (mAb) with an IC50of 0.64 ng/mL. Using the mAb, an immunochromatographic assay (ICA) was developed to analyze difenoconazole residues in pear and cucumber samples. The ICA exhibited LOD values of 2.60 and 2.30 ng/g for difenoconazole in pear and cucumber samples, respectively. The ICA showed average recoveries of difenoconazole ranging from 94.3% ± 3.6%–105.4% ± 1.6%, and CVs of 1.5–4.2% in cucumber and pear samples. When used to measure difenoconazole in samples, the ICA results were compatible with those detected by LC/MSMS. The results of this study support the idea that an ICA is a practical and effective tool for high-throughput and rapid analysis of difenoconazole residues in vegetables and fruits.