Development of broad-specific monoclonal antibody-based immunoassays for simultaneous ochratoxin screening in medicinal and edible herbs

The frequent occurrence of ochratoxins in food and herbs poses a considerable threat to consumer and animal health. Here, we generated a broad-specificity monoclonal antibody against three ochratoxins. Concentrations for 50% inhibition (IC50) for OTA, OTB, and OTC were 0.37, 0.23, and 2.24 ng/mL, respectively. In the two matrices, the proposed indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) exhibited a limit of detection (LOD) of 1.5 μg/kg for OTA and 1.0 μg/kg for OTB, respectively, whereas the cut-off levels of lateral flow immunoassay (LFIA) for OTA and OTB were respectively determined to be 1 and 0.25 ng/mL. As for OTC, the LOD of ic-ELISA and cut-off concentration of LFIA were 15.5 μg/kg and 8 ng/mL for milkvetch root and 37.5 μg/kg and 16 ng/mL for ginger, respectively. The real sample detection results by ic-ELISA and LFIA methods were validated via LC-MS/MS analysis. Therefore, the developed immunoassays are useful and effective tools for high-throughput screening and rapid on-site determination of ochratoxins in complex matrices.