Synthesis of a novel cross-linker doubles as a functional monomer for preparing a water compatible molecularly imprinted polymer

A new bifunctional monomer acting as both a cross-linker and a functional monomer was synthesized and applied in the preparation of water-compatible naproxen sodium imprinted polymers. The bifunctional feature was endowed by including quaternary ammonium as a cationic functionalized group in the middle for reaction with anionic molecules, together with two reactive vinyl groups on both ends for polymerization. The monomer owned superb water solubility, which was particularly conducive for preparing MIP in aqueous solution. Taking advantage of this double functionalized monomer, naproxen sodium imprinted polymers were manufactured in aqueous media. A small quantity of the new monomer embedded in the polymers demonstrated a significant influence on the binding performance of the MIPs. Results of rebinding experiments revealed that in water, the bifunctional monomer based MIPs exhibited much higher adsorption capacity (34.4 mg g−1) than acrylamide and 2-vinyl pyridine based MIPs (8.6 mg g−1 and 8.9 mg g−1, respectively). The maximum imprinting efficiency of the MIP reached 9.1. In addition, recoveries of template spiked in distilled water, drinking water and waste river water were 85%, 84% and 70%, respectively. We believe that the new bifunctional monomer can be extended to prepare more water compatible MIPs.