Carambola-like metal-AIEgen framework-based fluorescent lateral flow assay for the sensitive detection of zearalenone

A novel fluorescent lateral flow assay (FLFA) based on a zirconium-based metal aggregation-induced emission luminogen framework (Zr-MAF) is reported for the highly sensitive detection of zearalenone (ZEN) in cereals. A carambola-like Zr-MAF with a high fluorescence quantum yield of 36.9% was synthesized via a hydrothermal method using Zr⁴⁺ and 1,1,2,2-tetra(4-carboxylphenyl) ethylene (TCPE). The prepared Zr-MAF-labeled monoclonal antibody probe exhibited intense luminescence, robust stability, and high affinity toward ZEN, collectively contributing to a significant enhancement in detection sensitivity. Under optimal conditions, the Zr-MAF-FLFA achieved an ultralow detection limit (IC₁₀ = 0.014 ng/mL) and a sensitivity (IC₅₀) of 0.046 ng/mL, representing a 2.6-fold improvement over traditional gold nanoparticles-based FLFA. Notably, the assay exhibited significant cross-reactivity only with the ZEN homologues α-ZAL, β-ZAL, and β-ZOL, which shared similar electrostatic potentials and substantial 2D molecular similarities with ZEN. Furthermore, the proposed method was successfully applied to real food matrices, including flour, glutinous rice, sweet corn, and glutinous corn, yielding satisfactory recoveries ranging from 85.37% to 106.42%. With detection limits in these food samples (0.68-0.78 µg/kg) falling well below national regulatory limits, this work provides a robust analytical platform for trace mycotoxin monitoring in food safety.