A dual-monomer magnetic imprinted sorbent for fast removal and trace-level monitoring of hazardous aflatoxin B1.

Aflatoxin B1 (AFB1) is a highly toxic contaminant commonly found in foods, and its trace detection faces severe interference from complex matrices. To achieve efficient enrichment and rapid detection of AFB1, this study designed and synthesized a magnetic dual-functional monomer molecularly imprinted polymer (MMIP) with magnetic nanoparticles as the core and dummy templated ECC as the imprinting molecule. Through surface imprinting technology combined with methacrylic acid and styrene as dual functional monomers, an imprinted layer with specific recognition sites was constructed, while systematically optimizing synthesis conditions and adsorption-desorption parameters. The results demonstrated that the prepared MMIP exhibited high adsorption capacity (15.385 mg/g), rapid adsorption kinetics (reaching equilibrium within 2 min), good selectivity (imprinting factor of 2.40), large enrichment factor (23.8), and excellent reusability (only 6.1% decrease in adsorption efficiency after 10 cycles). Using this material as a MMIP-based magnetic dispersive solid-phase extraction combined with UPLC-MS/MS, an analytical method for trace AFB1 in complex food matrices was established, showing a linear range of 0.005-50 μg/L, a detection limit of 0.002 μg/L, and recovery rates ranging from 86.13% to 113.44%. This study provides a reliable strategy for the highly selective enrichment and rapid detection of trace AFB1 in complex food matrices.