Detection of aflatoxin B1 by a magnetic capture separator with time-resolved fluorescent microspheres

Abstract

In this study, a magnetic capture fluorescence separator(MC-FLS) based on the sandwich method was prepared using carboxyl-modified europium(III) fluorescent polystyrene microspheres (EuPMs) and carboxyl-modified magnetic microspheres (CMMs) for the rapid and specific capture and detection of aflatoxin B1(AFB1). Under the adsorption of an applied magnetic field, the antigen–antibody complexes (EuPMs@mAb-AFB1-mAb@CMMs) were enriched, forming a fluorescent zone at the bottom of the tube. The EuPMs were prepared by mini-emulsion polymerization, with an average diameter of 200 nm and monodispersed, which could be well applied in the separator. As determined by the semi-quantitative method, AFB1 showed good linearity in the range of 0.1–2 ng/mL (R2 = 0.9964). The result of LOD was 0.1146 ng/mL, and the result in the spiking test of real samples had a good correlation with the ELISA method. The results were positive for the specific detection of aflatoxin B1 and negative for the specific detection of aflatoxin M1 and aflatoxin B2, indicating that the method has good specificity and application prospects.