Molecular imprinting on amphiphilic folded polymers for selective molecular recognition in water

We report amphiphilic folded polymers with imprinted nanocavities for selective molecular recognition in water. For this, a molecular imprinting technique is applied to the polymer synthesis: amphiphilic polymer micelles interacting with template molecules are crosslinked in water to fix the folded architecture and memorize the template structure within the polymers; the removal of the templates provides imprint polymers bearing template-specific nanospaces. Here, a hydrophilic dye bearing two anionic groups, Orange G (OG), is used as a model template. For the imprinting, we design amphiphilic random copolymers bearing hydrophilic poly(ethylene glycol) (PEG) chains, hydrophobic olefin groups, and quaternary ammonium groups that can interact with the template. The copolymers were prepared by living radical polymerization and post functionalization. In the presence of OG and methyl blue (MB), the imprinted nanocavity polymers simultaneously capture both of the dyes in water. The total number of encapsulated dyes increased with increasing the number of polymer-bound quaternary ammonium groups. The selectivity of OG against MB increased with the crosslinking density, while imprint polymers encapsulated OG more efficiently than nonimprint polymers. © 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020 , 58, 215–224