By a facile reprecipitation method, organic nanoparticles with relatively uniform diameter of 200 nm of DHBIA {N,N'-di[4-(2'-benzo[d]thiazolyl)-3-hydroxyphenyl]5-tert-butylisophthalamide} have been prepared, which exhibited obvious aggregation induced enhanced emission. Based on the strong fluorescence of DHBIA in solid state, the red fluorescent compound PBDM {N,N'-bis-[(4-diphenylamino)- benzylidene]-diaminomaleonitrile} has been doped in the DHBIA nanoparticles and significant energy transfer was observed from DHIBA to PBDM. It was found that with increasing molar fraction of PBDM, the fluorescence could be tuned from green to red. Energy transfer in the doped nanoparticles was highly efficient and dominated by the Förster resonance mechanism. The emission tuning was much correlated to the intramolecular charge transfer in the PBDM molecules.

Key words: organic nanoparticle, aggregation induced enhanced emission, energy transfer, Fö, rster resonance mechanism