Skip to main content
eScholarship
Open Access Publications from the University of California

NEAR-IR TWO PHOTON MICROSCOPY IMAGING OF SILICA NANOPARTICLES FUNCTIONALIZED WITH ISOLATED SENSITIZED Yb(III) CENTERS

  • Author(s): Lapadula, Giuseppe;
  • Bourdolle, Adrien;
  • Allouche, Florian;
  • Conley, Matthew P.;
  • Maron, Laurent;
  • Lukens, Wayne W.;
  • Guyot, Yannick;
  • Andraud, Chantal;
  • Brasselet, Sophie;
  • Copéret, Christophe;
  • Maury, Olivier;
  • Andersen, Richard A.
  • et al.
Abstract

Bright nano objects emitting in the near infrared with a maximal cross section of 41.4 x 103 GM (Goppert Mayer), were prepared by implanting ca. 180 4,4 diethylaminostyryl 2,2 bipyridine (DEAS) Yb(III) complexes on the surface of 12 nm silica nanoparticles. The surface complexes ([DEAS Ln SiO2], Ln =Y,Yb) were characterized using IR, solid state NMR, UV Vis, EXAFS spectroscopies in combination with the preparation and characterization of similar molecular analogues by analytical techniques (IR, solution NMR, UV Vis, X ray crystallography) as well as DFT calculations. Starting from the partial dehydroxylation of the silica at 700 C on high vacuum having 0.8 OH.nm 2, the grafting of Ln(N(SiMe3)2)3 generate ≤SiO Ln(N(SiMe3)2)2, which upon thermal step and coordination of the DEAS chromophore yields (≤SiO)3Ln(DEAS). Surface and molecular analogues display similar properties, in terms of DEAS binding constants absorption maxima and luminescence properties (intense emission band assigned to a ligand centered CT fluorescence and life time) in the solid state, consistent with the molecular nature of the surface species. The densely functionalized nanoparticles can be dispersed via ultra-sonication in small ca. 15-20 nm aggregates (1 to 6 elementary particles) that were detected using two photon microscopy imaging at 720 nm excitation, making them promising nano objects for bio imaging.

Main Content
For improved accessibility of PDF content, download the file to your device.
Current View