Solid-phase extraction of aflatoxins using a nanosorbent consisting of a magnetized nanoporous carbon core coated with a molecularly imprinted polymer

A core consisting of nanoporous carbon (MNPC) and magnetized with Co₃O₄ was coated with a molecularly imprinted polymer (MIP) by atom transfer radical precipitation polymerization. Ethyl 3-coumarincarboxylate was used as a pseudo-template to give a MIP that has a fairly specific recognition capability for aflatoxins. Batch rebinding studies were carried out to determine the specific adsorption equilibrium and specific recognition. Extraction is achieved in a single step by mixing and vortexing the sample extract with the Co-MNPC@MIP. The loaded nanosorbent was then magnetically separated and eluted with acetonitrile/water (6/4, v/v). The aflatoxins were then quantified by HPLC. Under optimal conditions, the detection limits for aflatoxins typically are 0.05-0.07 ng mL^-1, recoveries from spiked corn are found to be 75.1 to 99.4%, and relative standard deviations range from 1.7 to 5.1 (n = 6). Graphical abstract Poly(methacrylic acid) was imprinted with the pseudo-template ethyl 3-coumarincarboxylate by atom transfer radical precipitation polymerization on the surface of cobalt-derived magnetic nanoporous carbon (Co-MNPC). This nanosorbent was used for the magnetic solid phase extraction of aflatoxins, followed by HPLC analysis.