Hydrophilic magnetic molecularly imprinted nanobeads for efficient enrichment and high performance liquid chromatographic detection of 17beta-estradiol in environmental water samples.

Novel magnetic molecularly imprinted nanobeads for 17β-estradiol (E2), namely, E2-MMINs, were synthesized by molecularly imprinted polymers on the surface of magnetic nanobeads in aqueous solvents. The hydrophilic nanobeads were set up by adopting carboxyl group-functionalized Fe3O4 nanoparticles as carriers, E2 as template molecule, and dopamine as functional monomer. The synthesized E2-MMINs were investigated in different aspects including synthesis conditions, physical and chemical properties, and adsorption conditions. The experimental results show that the E2-MMINs present not only thin imprinting layers, stable crystal form, and fast magnetic separation ability, but also rapid kinetics (20 min), high binding amount (41.48 mg g-1), satisfactory specificity (imprinting factor = 8.07), and favorable reusability (adsorption efficiency > 94.8% after reusing for 10 times). Moreover, the method employing E2-MMINs combined with high performance liquid chromatography for the specific enrichment and determination of trace E2 has been developed with the low LOD (0.008 μg L-1), and the application in environmental water samples has been proved. This work demonstrates that the proposed synthetic strategy is highly promising to the synthesis of hydrophilic nanobeads for efficient enrichment and detection of target molecule E2.