title: Single lanthanide-doped oxide nanoparticles as donors in fluorescence resonance energy transfer experiments.
abstract: We used lanthanide-ion doped oxide nanoparticles, Y(0.6)Eu(0.4)VO(4), as donors in fluorescent resonance energy transfer (FRET) experiments. The choice of these nanoparticles allows us to combine the advantages of the lanthanide-ion emission, in particular the long lifetime and the large Stokes shift between absorption and emission, with the detectability of the nanoparticles at the single-particle level. Using cyanine 5 (Cy5) organic molecules as acceptors, we demonstrated FRET down to the single-nanoparticle level. We showed that, due to the long donor lifetime, unambiguous and precise FRET measurements can be performed in solution even in the presence of large free acceptor concentrations. Highly efficient energy transfer was obtained for a large number of acceptor molecules per donor nanoparticle. We determined FRET efficiencies as a function of Cy5 concentration which are in good agreement with a multiple acceptor-multiple donor calculation. On the basis of the donor emission recovery due to acceptor photobleaching, we demonstrated energy transfer from single-nanoparticle donors in fluorescence microscopy experiments.
authors.affiliation: Laboratory for Optics and Biosciences, CNRS UMR7645, INSERM U696, Ecole Polytechnique, F-91128 Palaiseau Cedex, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Casanova
authors.forename: Domitille
authors.initials: D
authors.lastname: Giaume
authors.forename: Thierry
authors.initials: T
authors.lastname: Gacoin
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Boilot
authors.forename: Antigoni
authors.initials: A
authors.lastname: Alexandrou
mesh_terms: D002232:Carbocyanines / Q000494:pharmacology; D003198:Computer Simulation; D031541:Fluorescence Resonance Energy Transfer / Q000295:instrumentation* / Q000379:methods*; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D008027:Light; D008856:Microscopy, Fluorescence; D008956:Models, Chemical; D015233:Models, Statistical; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D010087:Oxides / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry; D013696:Temperature; D013997:Time Factors
chemical_list: D002232:Carbocyanines; D028581:Lanthanoid Series Elements; D010087:Oxides; C085321:cyanine dye 5