Materials science increasingly focuses on generating “smart”, i.e. highly functional, advanced matrices. Selective recognition can be implemented into man-made polymers by template-assisted synthesis. The method covers a surprising size range: it is possible to generate sensitivity and selectivity towards bivalent metal cations, such as Cu 2+ , in polyacrylate matrices. Despite the template being substantially smaller in size than the monomers, recognition can be achieved. Furthermore, acrylates can be templated with much larger species, such as influenza viruses. This leads to a nanostructured polymer surface that selectively re-binds the respective virion. Additional enhancement of sensitivity can be achieved by composite materials. Silver sulphide nanoparticles for instance show very appreciable affinity towards butanol vapors. When blending into butanol-imprinted polyurethane, the material incorporates three times more of the alcohol.