Molecular Imprinting-Defective UiO-66 for Selective Adsorption and Ultrasensitive Analysis of Aflatoxins in Food Crops

Aflatoxins (AFTs) pose a significant threat to the harvesting and storage of food crops and have adverse effects on human health. Combining metal–organic framework (MOF) materials and surface imprinting technology has been recognized as an effective strategy to fabricate selective adsorbents for the extraction of AFTs. In this study, molecularly imprinted MOFs (MI-d-UiO-66-NH2) were synthesized via surface imprinting. MI-d-UiO-66-NH2 exhibited selectivity toward AFTs owing to its abundant imprinted cavities and functional groups. The developed analytical method for AFTs, coupled with high-performance liquid chromatography tandem mass spectrometry, achieved low detection limits ranging from 0.001 to 0.150 ng mL–1. The recoveries of AFTs in four cereal samples spiked at three different concentrations (2.0, 5.0, and 10.0 μg kg–1) were 81.3% to 96.3%, with relative standard deviations of ≤9.5%. This study offers an effective approach for the accurate determination of trace AFTs in complex food matrices.