Site Sponsors
  • Oxford Instruments Nanoanalysis - X-Max Large Area Analytical EDS SDD
  • Strem Chemicals - Nanomaterials for R&D
  • Park Systems - Manufacturer of a complete range of AFM solutions
  • Technical Sales Solutions - 5% off any SEM, TEM, FIB or Dual Beam
Related Offers

Researchers Develop Superparamagnetic Gold Nanoshells

Published on May 12, 2010 at 2:13 AM

A solution-phase process has been developed by CNM users from the University of California at Riverside, working collaboratively with the Nanophotonics Group at the Argonne National Laboratory, for synthesizing stable multifunctional colloidal particles composed of a superparamagnetic Fe3O4 core, a gold nanoshell, and a mesoporous silica outer layer.

The unique porous silica layer is produced by a surface-protected etching process.

TEM images showing the evolution of Au nanoshells after 12 cycles of seeded growth.

By tuning the pore structure of the silica networks through etching, the shape and size of the gold nanoparticles can be controlled during the seeded growth, as well as their interparticle plasmon coupling.

Controllable interparticle coupling enables “hot spots” for surface enhanced Raman scattering.

The inclusion of responsive superparamagnetic Fe3O4 cores broadens the applications to include magnetically guided delivery and magnetic resonance imaging. The evolution from gold seeds to complete shells, and the corresponding change in plasmon bands, can be precisely controlled by the number of growth cycles and silica shell porosity.

More information: Q. Zhang, J. Ge, J. Goebl, Y. Hu, Y. Sun, and Y. Yin, Adv. Mater., 22, 1905 (2010).

Tell Us What You Think

Do you have a review, update or anything you would like to add to this news story?

Leave your feedback
Submit