Nature Commun. 3, 1088 (2012 )

Credit: © 2012 NPG

The structure and optical properties of π-conjugated polymers can be widely tuned though the choice of appropriate monomers for their synthesis. This versatility and easy processability make these polymers useful base materials for thin-film optoelectronic devices. However, preparation routes for conjugated polymer nanoparticles, which could be used in photonics or as biocompatible alternatives to inorganic nanoparticles for biomedical applications, have generally suffered from a large distribution of particle sizes, commonly referred to as polydispersity. Joris Sprakel and co-workers now report a synthesis scheme for monodisperse nanoparticles made from a range of conjugated polymers. They have adapted the Suzuki–Miyaura cross-coupling reaction — one of the most important routes for the synthesis of such compounds — to a dispersion polymerization process that enables the preparation of particles with well-defined sizes, tunable fluorescence wavelengths and controllable shape. The researchers demonstrate their self-assembly into a photonic crystal and show that the particles can be functionalized with carboxylic acid groups that allow for further coupling reactions for bioimaging.