Different fluorescent organic nanoparticles (FONs) from microemulsion were prepared with semi-continuous emulsion copolymerization of methyl methacrylate (MMA) and a polymerizable anionic surfactant. The diameters of particles ranged from 40 to 80 nm. The reactive surfactants were copolymerized with the main monomer. So the desorption of the surfactant from the polymer particles or the migration within the polymer film was impeded and avoided negative influences on the optoelectronic properties of the material. The microemulsion containing FONs was used in an ink-printing process to form different patterns. The photoluminescence properties of the films were investigated. It was expected that the approach of micro-droplet ink-jet printing of FONs would have bright future because no complicated preparation processes were required. (c) 2006 Elsevier B.V. All rights reserved.