Fluorescence immunoassay based on phage mimotope for nontoxic detection of Zearalenone in maize

Abstract

Zearalenone (ZEN) is one of the most common mycotoxin contaminants worldwide. In this study, a phage-based direct competitive fluorescence immunosorbent assay (P-dcFLISA) was developed for the detection of ZEN. In this P-dcFLISA, phage mimotope was used to replace chemically synthesized antigens to improve the safety of experiments. Furthermore, ZnCdSe/ZnS (core/shell) quantum dots (QDs) as fluorescent labeling material replaced chromogenic substrate, which are used in traditional ELISA. The 50% inhibition value (IC 50 ) of P-dcFLISA was 0.301 ng/ml, which was approximately 12-fold lower than that of phage-based indirect competitive enzyme-linked immunosorbent assay (P-icELISA). The limit of detection (LOD) of P-dcFLISA was 0.023 ng/ml and the detection range was 0.060-1.531 ng/ml. In the added recovery assay, recovery rate was 93.18-105.52%, with the coefficient variation (CV) ranging from 8.39% to 10.55%. The establishment of P-icFLISA not only save time, but also avoid the use of mycotoxins in the detection process, providing a safe method for the detection of mycotoxins. In conclusion, phage-based fluorescence immunoassay method has great potential application in ZEN detection and agricultural monitoring.