An efficient and biocompatible fluorescence resonance energy transfer system based onlanthanide-doped nanoparticles

Abstract

This work demonstrates an efficient and bio-friendly fluorescenceresonance energy transfer (FRET) system based on lanthanide-dopedinorganic nanoparticles. A facile aqueous route was used to synthesize theCePO4:Tb nanorodswith homogeneous colloidal dispersion, which emits a bright green light with a high quantum yield (∼0.36) and a longfluorescence lifetime (∼3.50 ms) upon UV excitation. Upon treatment ofCePO4:Tb with aqueous Rhodamine B (RhB), an efficient FRET occurs from theTb3 + tothe RhB molecules, giving rise to well resolved and ratiometric emissions of donors and acceptors,respectively, with an energy transfer efficiency of up to 0.85. When incubated with HeLa cells at37 °C, theCePO4:Tb treated with RhB shows bright intracellular luminescence, indicating that it can besuccessfully internalized inside the cells and the FRET remains in the living cells.Moreover, the cytotoxic measurements demonstrate good biocompatibility andlow cytotoxicity of our present FRET system. The advantages presented aboveincluding high quantum yield of donors, high energy transfer efficiency, ratiometricfluorescent emission and good biocompatibility, indicate the high potential of theCePO4:Tb/RhB FRET system for monitoring biological events.