Licensable Technologies : Physics & Chemistry

Gold and silver nanocluster synthesis utilizing dendrimer, peptides, and other biomolecules

Abstract
The synthesis of ultra fine particles of metal, which are referred to herein as clusters or nanoclusters, has been the subject of considerable interest. Small size may be needed for effective catalysts and is usually needed for high-resolution labeling of biological samples for transmission electron microscopic (TEM) examination. Small size is also expected to be important for fluorescent tags useful for labeling non-fluorescent biomolecules (proteins, nucleic acids, for example) and their assemblies that are not naturally fluorescent. Many fluorescent tags are so large that they perturb biomolecules as they interact with a binding partner, and tags might bleach rapidly, which can limit the time window that a molecular event for a biomolecule can be measured. Noble metal nanoclusters (gold or silver, for example) might be better tags than those currently available because noble metal nanoclusters exhibit a strong, size-dependent light emission, are very small, and can be attached to biomolecules. Some types of nanoclusters, such as gold nanoclusters, are highly fluorescent with a strong size-dependent emission and narrow emission bands. They have been prepared by the chemical reduction of gold ions in solution to give aggregates of atoms dispersed in the solvent..

Application(s)
- Any application that relies on the sensitive and quantitative detection of markers:
- Labeling of biomolecules for imaging and biosensing (currently being reduced to practice).
- Use as �smart dust� for tracking tagging and locating.
- Current applications of QDs including possibly energy harvesting.
- SERs substrates with confined and predicted hotspots

Advantages
- Dendrimer reactions do not produce competing nanoparticles, resulting in increased yield and decreased need for down stream processing (important for industrial scaling).
- The peptide substrates are designed/selected to be small encapsulating agents for protection of the gold cluster and facile conjugation to biomolecules.
- Small and predictable substrates for SERS.
- Toxicity of gold and silver nanoclusters is very low as compared to semiconducting quantum dots. Gold and silver clusters have been used medicinally for thousands of years. The industrial investment in modifying societal acceptance of new technology is huge and should be considered directly on development of new materials.

IP Status: Available both Exclusively and Non Exclusively

Commercialization Strategy: Available for either exclusive or non-exclusive license.

Reference Number: 842

S Number: DOE reference no.(s): 109,145

Patents & Applications:
Application(s) Filed

Posted: 08-13-2007

Contact
David Pesiri
Technology Transfer Division
Los Alamos National Laboratory
P.O. Box 1663, MailStop C334
(505) 665-7279
pesiri@lanl.gov