Indian origin scientists make 24-carat gold 'snowflakes'

Washington, October 14 (ANI): In an effort to make graphene more useful in electronics applications, two scientists of Indian origin have developed 24-carat gold 'snowflakes'.

The two scientists are Vikas Berry, a Kansas State assistant professor of chemical engineering and Kabeer Jasuja, a K-State doctoral student in chemical engineering.

Berry works with graphene, a carbon material only a single atom thick and discovered just five years ago.

To functionalize graphene with gold - thus controlling its electronics properties - Berry and Jasuja imbedded gold on graphene.

To do this, the engineers placed the graphene oxide sheets in a gold ion solution that had a growth catalyst. Here, the atomically thick sheets swim and bathe in a pool of chemicals.

"Graphene-derivatives act like swimming molecular carpets when in solution and exhibit fascinating physiochemical behavior," Berry said.

"If we change the surface functionality or the concentration, we can control their properties," he added.

They found that rather than distributing itself evenly over graphene, the gold formed islands on the sheets' surfaces. They named these islands snowflake-shaped gold nanostars, or SFGNs.

"So we started exploring how these gold nanostars are formed," Berry said.

"We found out that nanostars with no surface functionality are rather challenging to produce by other chemical processes. We can control the size of these nanostars and have characterized the mechanism of nucleation and growth of these nanostructures. It's similar to the mechanism that forms real snowflakes," he added.

Berry said that the presence of graphene is critical for the formation of the gold nanostars.

"If graphene is absent, the gold would clump together and settle down as big chunks," he said.

"But the graphene helps in stabilizing the gold. This makes the nanostars more useful for electronic applications," he added.

The discovery of these gold "snowflakes" on graphene shows promise for biological devices as well as electronics. Berry is attaching DNA to these gold islands to make DNA sensors.

Berry said that graphene-gold based DNA sensors will have enhanced sensitivity.

Chemically reducing graphene oxide to obtain graphene requires harsh chemicals that destroy the DNA.

"Now we can use the harsh chemicals on graphene oxide imbedded with gold to obtain graphene with gold islands. Then we can use these gold islands to functionalize DNA," said Berry. (ANI)