Fluorescent microsphere immunochromatographic sensor for ultrasensitive monitoring deoxynivalenol in agricultural products

A rapid lateral flow fluorescence microsphere immunoassay test strip (FM-ICTS) for the detection of deoxynivalenol (DON) residues in different agricultural products was established based on competitive immunoreactivity. For this purpose, two ultra-sensitive anti-DON monoclonal antibodies (mAbs) were prepared and characterized, displaying high affinity and sensitivity. mAb 3F5 had a 50%-inhibitory concentration (IC50) of 1.93 ng/mL, an affinity constant of 2.2 ? 109 L/mol, and a limit of detection (LOD) of 0.29 ng/mL for DON. The mAb was covalently coupled to carboxylate modified FMs and these were used as markers in a competitive immunochromatography assay. The FM-mAbs captured on the T-line represent the fluorescence intensity detected under UV light and can be quantified by a fluorescence reader. Under optimal conditions, the visual LODs for DON by the FM immunoassay was 2.5 ng/mL and the cut-off value was 25 ng/mL and the recovery for spiked DON in agricultural samples was 90.20%-107.32%. The results show that this FM-ICTS method is simple, reliable, and sensitive, and represents a good strategy for food safety analysis and can be used for the detection of DON residues in agricultural products.

Automated summary

A rapid lateral flow fluorescence microsphere immunoassay test strip (FM-ICTS) was established for the detection of deoxynivalenol (DON) residues in agricultural products based on competitive immunoreactivity. The method, utilizing highly sensitive antibodies and fluorescent markers, is simple, reliable, and sensitive for food safety analysis.