Multifunctional hybrid silica nanoparticles based on [Mo₆Br₁₄]²⁻ phosphorescent nanosized clusters, magnetic γ-Fe₂O₃ and plasmonic gold nanoparticles

Nicolas Nerambourg (1, 2) , Tangi Aubert (1) , Chrystelle Neaime (1) , Stéphane Cordier (1) , Michel Mortier (3) , Gilles Patriarche (4) , Fabien Grasset (1)

1 ISCR - Institut des Sciences Chimiques de Rennes
2 SRSMC - Structure et Réactivité des Systèmes Moléculaires Complexes
3 IRCP - Institut de Recherche de Chimie Paris
4 LPN - Laboratoire de photonique et de nanostructures

We report on the synthesis, characterization and photophysical study of new luminescent and magnetic hybrid silica nanoparticles. Our method is based on the co-encapsulation of single maghemite γ-Fe2O3 nanoparticles and luminescent molybdenum cluster units [Mo6Br(i)8Br(a)6](2-) through a water-in-oil (W/O) microemulsion technique. The as-prepared core-shell [Cs2Mo6Br14-γFe2O3]@SiO2 nanoparticles (45-53 nm) possess a single magnetic core (6, 10.5 or 15 nm) and the cluster units are dispersed in the entire volume of the silica sphere. The [Cs2Mo6Br14-γFe2O3]@SiO2 nanoparticles have a perfect spherical shape with a good monodispersity and they display red and near-infrared (NIR) emission in water under UV excitation, whose intensity depends on the magnetic core size. The hybrid nanoparticles have been characterized by transmission electron microscopy (TEM), high annular angular dark field scanning transmission electron microscopy (HAADF-STEM), energy-dispersive X-ray spectroscopy (EDX), UV-Vis-NIR spectroscopy and magnetometer SQUID analysis. Small gold nanoparticles were successfully nucleated at the surface of the hybrid silica nanoparticles in order to add plasmonic properties.

Mots clés: Silica nanoparticles; Metal atom clusters; Luminescent nanoparticles; Magnetic nanoparticles

Domaines: Matériaux

Nicolas Nerambourg, Tangi Aubert, Chrystelle Neaime, Stéphane Cordier, Michel Mortier, et al.. Multifunctional hybrid silica nanoparticles based on [Mo₆Br₁₄]²⁻ phosphorescent nanosized clusters, magnetic γ-Fe₂O₃ and plasmonic gold nanoparticles. Journal of Colloid and Interface Science, 2014, 424, pp.132-40. ⟨10.1016/j.jcis.2014.03.008⟩. ⟨hal-01020577⟩