One-Step Synthesis of Polydopamine-Coated Dummy Molecularly Imprinted Polymers on the Surface of Fe3O4 for Selective Extraction and Enrichment of Aflatoxin B in Foods Prior to High-Performance Liquid Chromatography Detection

Abstract A new specific sorbent entitled molecularly imprinted polymer (Fe3O4@PDA MIP) was fabricated on the surface of ferroferric oxide nanoparticles with the dummy template of 5,7-dimethoxycoumarin through self-assembly of dopamine which is efficient for recognition and determination of aflatoxin B in food samples coupled with UPLC-FLD with a large volume flow cell. The prepared MIPs were characterized, and the adsorption properties were evaluated. The maximum adsorption capacities were 0.46 mg/g for aflatoxin B1 and 0.047 mg/g for aflatoxin B2. Under optimized conditions, the calibration plots are linear in the range of 0.005–0.5 and 0.001–0.1 ng/mL with LODs of 0.0024 and 0.0004 ng/mL for aflatoxin B1 and aflatoxin B2, respectively. The recoveries from spiked samples are 89.0–105.0% with RSDs of 5.6–7.7% in case of corn, peanut and edible oil. And after 7 cycles, the adsorption capacity of the MIPs did not decrease significantly.