Molecularly Imprinted Polymer-Coated Metal-Organic Cages as Ambient Ionization Probes for Rapid Detection of Aflatoxins in Peanut and Corn

A novel integrated ion source component based on molecularly imprinted polymer-coated metal-organic cages (SSS@MOC@MIP) was developed for rapid aflatoxin (AFs) detection via ambient mass spectrometry (AMS). By leveraging the synergistic effects of a high-surface-area MOC scaffold which endows the material with exceptional adsorption capacity and specific imprinted cavities, this integrated probe enables simultaneous enrichment, purification, and ionization on a single device. The method effectively suppressed severe matrix interferences from peanut oil and corn starch (matrix effects within ±15.3%) and achieved a high imprinting factor of 3.27. Under optimized conditions, the SSS@MOC@MIP-AMS method allowed for rapid quantification within 1 minute, with low limits of detection (0.11–0.54 μg/kg) and satisfactory recoveries (79.05%–108.29%). The probe exhibited robust reusability for at least six cycles. Practical application to commercial samples confirmed its reliability, offering a powerful and high-throughput tool for the rapid screening of trace-level aflatoxins in complex food matrices.