One-Pot Production of Fluorescent Surface-Labeled Polymeric Nanoparticles via Miniemulsion Polymerization with Bodipy Surfmers

New molecules combining the functionalities of surface activity, polymerizability, and fluorescent properties within one molecule that could be seen as a fluorescent surfmer ( surf actant and mono mer ) were successfully synthesized. A long hydrocarbon tail capped with a methacrylamide unit was anchored to a mono- or double-sulfonated Bodipy core. Time-resolved fluorescence measurements in aqueous solutions of the dyes enable one to trace the micelle formation and to find strong polarity dependence of fluorescence properties of the dyes. By using these molecules, polystyrene nanoparticles with fluorescent interfaces were synthesized via miniemulsion polymerization. The surfmers can be used alone or as surfactant additional to sodium dodecyl sulfate that provides stable emulsions and dispersions with a wide range (100–250 nm) of realizable particle sizes after polymerization. All synthesized nanoparticles showed bright fluorescence and can be easily investigated with conventional fluorescent confocal microscopy. Only the fluorescence of particles with double-sulfonated surfmer used is strongly sensitive to fluorescent quenchers as sodium iodide or methyl viologene dissolved in the continuous phase. In contrast, the fluorescence of nanoparticles labeled with the monosulfonated surfmer is only weakly quenched that might be explained by specific orientation of the Bodipy core at particle/water interface.