Non-competitive immunoassay for zearalenone based on phage display developed recombinant antibody and anti-immunocomplex peptide.

Zearalenone (ZEN) is a widely distributed mycotoxin with potent estrogenic activity. Detecting ZEN is crucial for assessing its potential health risks. This study developed a highly sensitive non-competitive magnetic phage anti-immunocomplex immunoassay (Nc-MPHAIA) for ZEN detection, utilizing the anti-ZEN single-chain variable fragment (ScFv) and anti-immunocomplex peptide (AIcP), both of which were screened using phage display technology. The method exhibited a limit of detection of 0.005 ng/mL, which was 112 times lower than that of the conventional competitive immunoassay using the same ScFv and the chemosynthetic antigen ZEN-OVA. Validation studies demonstrated excellent recovery rates in spiked corn samples (intra-assay: 84.04-109.95 %; inter-assay: 89.70-99.59 %). Additionally, the Nc-MPHAIA results for ZEN in natural samples were consistent with those obtained via high-performance liquid chromatography, which demonstrated good reliability of the established assay.