Solvent-responsive polymer nanocapsules with controlled permeability: encapsulation and release of a fluorescent dye by swelling and deswelling.

A solvent-responsive polymer nanocapsule swells and deswells in response to a change in solvent composition, and the permeability of the shell of the nanocapsule can be controlled simply by swelling and deswelling; encapsulation and release of a fluorescent dye is achieved by a swelling-deswelling-swelling cycle.