Abstract:

Core-shell magnetic molecularly imprinted polymer (MIP) nanoparticles (NPs), in which a rhodamine
6G-imprinted layer was coated on modified Fe3O4 NPs, were synthesized by combined techniques of magnetic separation
and surface molecular imprinting. The Fe3O4@MIPs were studied by re-binding experiments, such as adsorption kinetics,
adsorption isotherm, molecular identification, and applied to the separation and enrichment of rhodamine 6G in food
samples. Under the action of additional magnetic field, the polymers could be quickly separated from the sample matrix and
greatly improved the efficiency of experiments. The results showed that the core-shell Fe3O4@MIPs had a fast adsorption
equilibrium, highly improved imprinting capacity and significant selectivity; the recoveries were in the range of 92.3%–
99.2% with relative standard deviation between 0.85% and 1.12%, and the detection limit was 0.003 8 μg/mL (RSN=3). Thus,
the core-shell Fe3O4@MIPs could be used as a solid-phase extraction material to conveniently detect the illegal addition of
rhodamine 6G in food samples.

Key words: core-shell, magnetic molecularly imprinted polymer, solid-phase extraction, rhodamine 6G