Molecularly imprinted nanoparticles prepared by core-shell emulsion polymerization

Submicron core-shell polymer particles, with molecularly imprinted shells, were prepared by a two-stage polymerization process. Particles of this type , prepared with a cholesterol-imprinted ethyleneglycol dimethacrylate shell and in the absence of porogen, were found to be 76 nm in diameter with a s urface area of 82 m(2) g(-1) Cholesterol uptake from a 1 mM solution in iso hexane was measured at both 10 and 30 mg mL(-1), with the imprinted polymer showing considerable binding (up to 57%). Imprinted but not hydrolyzed and hydrolyzed nonimprinted polymers showed very low uptakes (less than or equ al to 4.5%) and a phenol-imprinted polymer showed reduced binding (36%) und er the same conditions. Imprinted shells were also prepared over superparam agnetic polymer cores and over magnetite ferrocolloid alone. The cholestero l binding to magnetic particles was very similar to that of equivalent nonm agnetic materials. Magnetic particles could be sedimented in as little as 3 0 s in a magnetic field. (C) 2000 John Wiley & Sons, Inc.