Fe3O4@Au magnetic SERS nanotags-based vertical flow immunoassay for simultaneous detection of fumonisin B1, aflatoxin B1 and deoxnivalenol.

Agricultural products are usually contaminated by various mycotoxins, the rapid and sensitive detection of mycotoxins at the early stage is significant for food safety and human health. Here, we develop a rapid and ultrasensitive surface-enhanced Raman scattering-based vertical flow assay (VFA) for simultaneous detection of multiple mycotoxins by using Fe3O4@Au magnetic SERS nanotags. In this competitive immunoassay, three test zones are designed on the sensing membrane, and modified with multiple capture antigens. Moreover, three kinds of specific monoclonal antibodies conjugated Fe3O4NBA@Au, Fe3O44-MBA@Au, and Fe3O4DNTB@Au SERS nanotags were synthesized as probes to identify fumonisin B1 (FB1), aflatoxin B1 (AFB1), and deoxnivalenol (DON), respectively. The magnetic nanoparticles have three following merits: specific recognition, SERS signal enhancement, and magnetic enrichment of the target without any sample preprocessing steps. The limits of detection for FB1, AFB1, and DON are 0.053, 0.028 and 0.079 pg mL-1, respectively, which are 1000 times more sensitive than those conventional standard colloidal gold methods. Furthermore, the proposed biosensor is easy to operate, rapid, accurate, and can achieve high throughput and is expected to be a powerful analytic platform for early detection of multiple mycotoxins in food.