Development and Application of High-Sensitivity Magnetic Fluorescence Immunochromatographic Test Strip for Detection of Deoxynivalenol

This study aimed to develop an immunochromatographic test strip model based on magnetic fluorescence nanomaterials in order to make up for the shortcoming of lateral flow immunoassay and provide technical support for the development of more sensitive rapid immunological assays. Using deoxynivalenol (DON) as the target, carboxyl-modified superparamagnetic particles were prepared by the solvothermal method. The magnetic particles, green fluorescent protein and anti-DON monoclonal antibody were coupled by the carbodiimide method to prepare magnetic fluorescent antibody probe. A magnetic fluorescence immunochromatographic test strip was established with DON-bovine serum albumin (BSA) as the test line. Meanwhile, a colloidal gold immunochromatographic test strip was established with colloidal goldlabeled anti-DON monoclonal antibody as the probe and DON-BSA as the test line. The magnetic fluorescence antibody probe exhibited good magnetic and fluorescent properties and antibody reactivity. The regression equation of the magnetic fluorescence immunochromatographic test strip was y = -0.562x + 0.921, R² = 0.990. The half maximal inhibitory concentration (IC₅₀) was 5.611 ng/mL, and the detection limit was 1.089 ng/mL. The sensitivity of the colloidal gold immunochromatographic test strip was 500 ng/mL with naked eyes, the regression equation was y = -0.543x + 1.485, R² = 0.991, the IC₅₀ was 65.16 ng/mL, and the detection limit was 11.94 ng/mL. The sensitivity of the magnetic fluorescence immunochromatographic test strip was 10.96 folds higher than that of the colloidal gold immunochromatographic test strip. The magnetic fluorescence immunochromatographic test strip allowed simultaneous sample enrichment and fluorescence signal detection and was successfully used in the detection of DON with high sensitivity. This study may lay the foundation for the application of magnetic fluorescence nanoparticles in the field of immunochromatographic assay.