Rainbow latex microspheres lateral flow immunoassay with smartphone-based device for simultaneous detection of three mycotoxins in cereals

The coexistent pollution of multiple mycotoxins displays a synergistic toxicity effect that significantly threatens human health. Therefore, it is essential to establish a rapid detection method for multi-mycotoxins in food. In this study, red, green, and blue latex microspheres (LMs) were applied as the aflatoxin B1 (AFB1), T-2 toxins (T-2), and zearalenone (ZEN) antibodies labeled tracer, respectively. Based on the principle of spatial resolution, a rainbow “traffic light” pattern latex microspheres lateral flow immunoassay (LMs-LFIA) integrated with a portable and user-friendly smartphone-based device was first developed to detect three kinds of mycotoxins simultaneously. The cut-off values of the method for AFB1/T-2/ZEN in cereals were 1/15/40 μg kg-1, the limits of detection were 0.04/0.40/1.21 μg kg-1, respectively. The recoveries ranged from 82.1% to 107.5%, with the coefficient of variation from 3.0% to 8.1%. A parallel analysis in 26 naturally contaminated cereal samples was confirmed by commercial ELISA kits; the results showed a good correlation (R2＞0.99), indicating the practical reliability of the rainbow LMs-LFIA. This method provided a visually enjoyable, portable, and sensitive detection mode for multi-target detection of mycotoxins or other small molecule hazard factors in food.