Application of dispersive solid-phase extraction materials based on nucleic acid aptamer-modified magnetic MIL-100(Fe) in the detection of zearalenone.

Zearalenone (ZEN), a mycotoxin produced by fungi of the genus Fusarium, is widely present in animal feeds and human foods, posing a serious hazard to human health. Herein, a zearalenone aptamer-functionalized magnetic metal-organic framework material (ZEN-Apt@MMIL-100(Fe)) was constructed and applied for the rapid enrichment of ZEN, coupled with high-performance liquid chromatography (HPLC) for ultrasensitive detection. By a self-templating method, magnetic MIL-100(Fe) was formed by self-assembly of sodium citrate-modified FeO particles as nuclei with homobenzoic acid, which was bonded to amino-modified zearalenone nucleic acid aptamer via amide reaction to realize a specific recognition function. The magnetic dispersive solid-phase extraction and HPLC method was established using this material, with the linear range of 5 to 200 μg/L (R = 0.997) and the limit of detection of 2.92 μg/L. The method was applied to detect ZEN in maize and wheat samples, with spiked recoveries ranging from 81.7% to 98.2% at spiking levels of 25 μg/L, 50 μg/L, and 100 μg/L. The method is able to realize the selective and rapid enrichment and detection of trace ZEN in wheat and maize through the synergistic action of aptamer-specific recognition and magnetic MOFs, which provides a sensitive and reliable analytical strategy for food security monitoring.