Development of a screening fluorescence polarization immunoassay for simultaneous detection of fumonisin B1 and B2 in maize.

We report the development of a screening fluorescence polarization immunoassay (FPIA) for simultaneous detection of fumonisin B1 (FB1) and B2 (FB2) in maize. Three FB1 tracers including FB1-FITC, FB1-5-DTAF and FB1-TRX were synthesized and studied to select appropriate tracer-antibody pairs using seven previously produced monoclonal antibodies (mAbs). An FPIA employed the pair of FB1-FITC and mAb 4B9 showing 98.9% of cross-reactivity (CR) towards FB2 was used to simultaneously detect FB1 and FB2. Maize flour samples were extracted with methanol/water (2:3, v/v). After optimization, the FPIA revealed a limit of detection (LOD) of 157.4 μg kg-1 for FB1 and 290.6 μg kg-1 for FB2, respectively. Recoveries were measured for spiked samples of FB1 or FB2 separately, ranging from 84.7% to 93.6%, with coefficient of variation (CV) less than 9.9%. Total time needed for FPIA including sample pretreatment was less than 30 min. The FPIA was used to screen naturally contaminated maize samples. Results detected by FPIA showed good agreement with that of HPLC-MS/MS with a fit of R2 0.99 for simultaneous detection of FB1 and FB2. The established method offered a rapid, simple, sensitive and high-throughput screening tool for detection of FBs in maize.