Highlight: Superparamagnetic Gold Nanoshells with Tunable Optical Properties

May 11, 2010
Superparamagnetic Gold Nanoshells with Tunable Optical Properties
TEM images showing the evolution of Au nanoshells after 12 cycles of seeded growth.

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 layer is produced by a surface-protected etching process.

By tuning the pore structure of the silica networks through etching, the shape and size of the 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 . 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.

Explore further: Microfluidics and nanofluidics research provide inexpensive ways to analyze blood and filter water (w/ Video)

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

add to favorites email to friend print save as pdf

Related Stories

Labeling Cells with Magnetic Nanoparticles

Feb 20, 2007

Investigators at the German Cancer Research Center have developed silica-coated iron oxide nanoparticles that allow for cell tracking in a live animal using magnetic resonance imaging (MRI). More sensitive methods for tracking ...

Shimmering Colours Which Change With Temperature

Dec 02, 2005

Scientists at the Max Planck Institute of Colloids and Interfaces have used ion bombardment and gold metallisation to produce a new family of particles whose bonding behaviour can be chemically tailored. With ...

New insight to demineralization

Jul 07, 2008

From toothpaste to technology, noncrystalline or amorphous silica is an active ingredient in a myriad of products that we use in our daily lives. As a minor, but essential component of vertebrate bone, an understanding of ...

Coupling of Single Quantum Dots to Smooth Metal Films

Jul 20, 2009

Scientists at Argonne National Laboratory's CNM Nanophotonics Group have measured how light emission from individual colloidal semiconductor nanocrystals, or quantum dots, is modified when in proximity to ...

Silver proves its mettle for nanotech applications

Mar 19, 2010

The self-assembling properties of the DNA molecule have allowed for the construction of an intriguing range of nanoscale forms. Such nanoarchitectures may eventually find their way into a new generation of ...

Recommended for you

User comments : 0