Preparation of Fluorescence Tunable Polymer Nanoparticles by One-step Mini-emulsion

Fluorescence tunable polymer nanoparticles were prepared by incorporating two hydrophobic fluorescent dyes (9, 10-diphenylanthracene: DPA and nitrobenzoxadiazolyl: NBD) into polymethylmethacrylate (PMMA) nanoparticles via one-step mini-emulsion polymerization method. The prepared fluorescent nanoparticles exhibit the spectral properties of both DPA and NBD dye, indicating that the two fluorophores have been incorporated into the nanoparticles. The nanoparticles greatly enhance the fluorescence emission of the two hydrophobic dyes in aqueous media probably by providing good protection of the dye molecules in the polymer nanoparticles matrix. Moreover, by varying the doping ratio of the two hydrophobic dyes, the polymer nanoparticles exhibit tunable and distinguishable emission characteristics under a single wavelength excitation via occuring fluorescence resonance energy transfer (FRET).