Development of a lateral flow immunoassay for rapid quantitation of carbendazim in agricultural products

• A novel monoclonal antibody against carbendazim was produced and characterized. • A TRF-LFIA was developed and applied to the sensitive quantitation of carbendazim. • Rapid on-site detection of carbendazim in rice and tobacco matrices was achieved. • The quantitative results of TRF-LFIA were in good agreement with that of LC-MS/MS. Carbendazim (CBZ) is a systematic fungicide widely used in agriculture, and its residue issue not only affects trade of agricultural products but also causes potential risks to consumers. In this work, a lateral flow immunoassay based on time-resolved fluorescence microspheres (TRFMs) labeled monoclonal antibody (mAb) was developed for rapid quantitation of CBZ. Specifically, starting with the careful design and synthesis of hapten using 2-aminobenzimidazole and glutaric anhydride as reactants, a novel and specific mAb against CBZ was produced and characterized. Subsequently, using TRFMs as signal probe, a time resolved fluorescence lateral flow immunoassay (TRF-LFIA) was constructed through covalent coupling of mAbs and TRFMs. The developed TRF-LFIA could achieve rapid detection of CBZ within 10 min, and its applicability to the quantitation of CBZ in agricultural products (rice and tobacco) was evaluated. The limits of detection (LODs) in rice and tobacco were 0.41 ng/mL (0.012 mg/kg) and 0.56 ng/mL (0.017 mg/kg), respectively. The spiked recoveries in blank rice and tobacco were ranged from 82.0% to 113.0% with relative standard deviations of 2.0–11.8%. The quantitative results of CBZ in naturally incurred tobacco measured by TRF-LFIA were confirmed by liquid chromatography-tandem mass spectrometry, and the results were consistent. The developed TRF-LFIA could provide a sensitive, rapid and cost-effective method for on-site monitoring of CBZ in agricultural products.