Wednesday, July 8, 2009

Tunable Hollow Metal Nanorods- A Novel Approach

An adaptable approach for preparing nano-materials of engineered size, shape, composition, and porosity has been developed by researchers at Simon Fraser University, Canada.
They have developed a simple technique to engineer hollow metal nanostructures of well-defined properties.
The nanostructures have a tunable diameter, length, and shape that are defined by the sacrificial template used to grow the hollow product. The electrochemically synthesized templates are
regular, polycrystalline cylindrical silver nanorods with dimensions dictated by both the physical mold that confines their growth as well as the conditions for electrodeposition. This template can be selectively etched to isolate a porous hollow nanostructure.
These robust hollow metal nanostructures have potential applications in the selective delivery and release of reagents such as medicinal drugs.
The photothermal properties of metal nanostructures have been investigated for destroying cancer cells.


Reference: ACSNano,VOL.3,NO. 6, 1365–1372 , 2009

Tuesday, July 7, 2009

Thiolate Ligand Stabilization of Gold Nanoparticles

Polydentate amphiphilic thiols possess excellent properties for gold nanoparticle stabilization and functionalization and resistant to exchange reactions.

Gold -thiol bond is generally believed to be one of tightest link for gold surface functionalization and well-known for its thermodynamic stability. In biological environment, where thiol groups are presents, prevention of thiolate-thiol excahnge is also an important consideration. In such situations, a reliable functionalization can provide kinetic stability against ligand exchange.

Different efforts have been made to improve the exchange stability of thiolate ligands on gold nanoparticles.
Recently, German scientist have synthesized the trithiol
1,1,1-tris(mercaptomethyl)undecane
as a model to investigate the particle stabilization and exchange properties of tripodal organothiolate.

for further details, refer to: Chem. Commun., 2006, 3693–3695 | 3693