Featured Research

from universities, journals, and other organizations

24-carat gold 'snowflakes' improve graphene's electrical properties

Date:
November 28, 2009
Source:
Kansas State University
Summary:
In an effort to make graphene more useful in electronics applications, engineers have made a golden discovery -- gold "snowflakes" on graphene.

The above image shows the way in which snowflake-shaped gold nanostars cluster on a graphene sheet.
Credit: Kansas State University, Department of Chemical Engineering

In an effort to make graphene more useful in electronics applications, Kansas State University engineers made a golden discovery -- gold "snowflakes" on graphene.

Related Articles


Vikas Berry is a K-State assistant professor of chemical engineering who 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 Kabeer Jasuja, a K-State doctoral student in chemical engineering, 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."

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."

Berry said 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."

In July, Jasuja and Berry published their work in the journal ACS-Nano.

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. He is joined by Nihar Mohanty, a doctoral student in chemical engineering, and undergraduate researcher Ashvin Nagaraja, a senior in electrical engineering. Nagaraja is a 2004 Manhattan High School graduate.

Berry said 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."

Berry also is using graphene in conjunction with microwaves. He and Jasuja are "cooking" the graphene sheets as another way to produce particles on the material's surface.

Some of Berry's other graphene research involves using the modified graphene sheets to compartmentalize a coagulating solution, thus stabilizing it. His group has recently used hydrides to reduce graphene oxide to produce reduced graphene oxide in the matter of a few seconds. The graphene produced in this way can remain stable in the solution for several days. Further results will shortly appear in the journal Small

Discovered only five years ago, graphene has captured the attention of a large number of researchers who are studying its exceptional electrical, mechanical and optical properties, Berry said. His research group is among the few studying the material's interfacial properties and biological applications.

"We're entering a new era," Berry said. "From the zero-dimensional or one-dimensional molecular or polymer solutions, we are now venturing into the two-dimensional graphene solutions, which have fascinating new properties."


Story Source:

The above story is based on materials provided by Kansas State University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Kabeer Jasuja and Vikas Berry. Implantation and Growth of Dendritic Gold Nanostructures on Graphene Derivatives: Electrical Property Tailoring and Raman Enhancement. ACS Nano, 2009; 3 (8): 2358 DOI: 10.1021/nn900504v

Cite This Page:

Kansas State University. "24-carat gold 'snowflakes' improve graphene's electrical properties." ScienceDaily. ScienceDaily, 28 November 2009. <www.sciencedaily.com/releases/2009/10/091013112521.htm>.
Kansas State University. (2009, November 28). 24-carat gold 'snowflakes' improve graphene's electrical properties. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2009/10/091013112521.htm
Kansas State University. "24-carat gold 'snowflakes' improve graphene's electrical properties." ScienceDaily. www.sciencedaily.com/releases/2009/10/091013112521.htm (accessed October 25, 2014).

Share This



More Matter & Energy News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com
Real-Life Transformer Robot Walks, Then Folds Into a Car

Real-Life Transformer Robot Walks, Then Folds Into a Car

Buzz60 (Oct. 24, 2014) Brave Robotics and Asratec teamed with original Transformers toy company Tomy to create a functional 5-foot-tall humanoid robot that can march and fold itself into a 3-foot-long sports car. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Police Testing New Gunfire Tracking Technology

Police Testing New Gunfire Tracking Technology

AP (Oct. 24, 2014) A California-based startup has designed new law enforcement technology that aims to automatically alert dispatch when an officer's gun is unholstered and fired. Two law enforcement agencies are currently testing the technology. (Oct. 24) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins