Ovalbumin antibody-based fluorometric immunochromatographic lateral flow assay using CdSe/ZnS quantum dot beads as label for determination of?T-2 toxin

摘要： This work describes an anti-ovalbumin antibody-based lateral flow immunoassay (LFI) for T-2 toxin. The antibody uses a coating antigen as a bifunctional element for universality and introduces preincubation to improve the detection limits of the method. T-2 toxin and ovalbumin-modified T-2 toxin competitively binds on the anti-T-2 toxin monoclonal antibody modified on CdSe/ZnS quantum dot beads during preincubation. The modified T-2 toxin acts as a bifunctional element that forms immuno complexes during preincubation and combines with anti-ovalbumin antibody coated in the test line through the ovalbumin terminal. Fluorescence is detected at 610 nm on the test zone following photoexcitation at 365 nm. It has a reverse dose-effect relationship with the amount of T-2 toxin. The calibration plot is linear in the 20–110 fg mL?1 T-2 toxin concentration range, and the limit of detection (LOD) is 10 fg mL?1, which is lower by 8-fold than that of the traditional LFI system (LOD 80 fg mL?1) and one order of magnitude than those of LFIs with labels of colloidal gold nanoparticles (LOD 150 fg mL?1) or fluorophores (LOD 190 ng mL?1). Universality was verified through aflatoxin B1 detection using the established ovalbumin antibody-based LFI system (LOD 10 fg mL?1). The performance of the method was compared with that of established systems and a commercial ELISA kit (LOD 360 fg mL?1).