abstract
Bimodal magnetic resonance imaging (MRI)/optical probes for bioimaging were obtained by grafting two types of lanthanide metal ions, Gd3+ and Eu3+/Tb3+, on the surface of SiO2 nanoparticles. The resulting systems were endowed with relaxometry and photoluminescent properties, respectively. Grafting a pyridine-based aromatic backbone on to the silica surface enhances the emission quantum yield of the Eu3+-containing nanoparticles fivefold compared to similar systems that bear no aromatic antennae. The emission properties of the mixed Ln3+/Gd3+-based nanoparticles are not influenced by the presence of Gd3+. The relaxometric properties of these samples are slightly better than the properties of commercial [Gd(DTPA)]2 (DTPA = diethylenetriaminepentaacetate). When taken up by RAW 264.7 cells (mouse macrophage cell line), such bimodal probes exhibit both T1-weighted MRI increased contrast and fluorescence tracking.
keywords
CONTRAST AGENTS; QUANTUM DOTS; GAMMA-AMINOPROPYLTRIETHOXYSILANE; INORGANIC NANOPARTICLES; LANTHANIDE COMPLEXES; LUMINESCENT PROBES; RADIO-OPAQUE; FLUORESCENT; SURFACE; EUROPIUM(III)
subject category
Chemistry
authors
Pinho, SLC; Faneca, H; Geraldes, CFGC; Rocha, J; Carlos, LD; Delville, MH
our authors
João Rocha
Full Professor
Luís Carlos
Full professorProjects
Nanostructured Photoluminescent rare-earth nanotubes and microporous silicates (PTDC/CTM/73243/2006)
acknowledgements
This work was supported by the Portuguese Fundacao para a Ciencia e Tecnologia (FCT) (project numbers PTDC/CTM/73243/2006 and SFRH/BD/38313/2007, grant to S. L. C. P.), the French Centre National de la Recherche Scientifique (CNRS), the Region Aquitaine France, Fundo Europeu de Desenvolvimento Regional (FEDER), the European Union (EU), COST Action D38