Featured Research

from universities, journals, and other organizations

Gold Nanostars Outshine The Competition

Date:
October 20, 2008
Source:
National Institute of Standards and Technology
Summary:
Scientists used surface-enhanced Raman spectroscopy to demonstrate that gold nanostars exhibit optical qualities that make them superior for chemical and biological sensing and imaging. These uniquely shaped nanoparticles may one day be used in a range of applications from disease diagnostics to contraband identification.

NIST scientists found that gold and silver nanostars improved the sensitivity of Surface Enhanced Raman Spectroscopy (SERS) 10 to 100,000 times that of other commonly used nanoparticles. These uniquely shaped nanoparticles may one day be used in a range of applications from disease diagnostics to contraband identification. Color added for clarity.
Credit: NIST

Novel nanoparticles being tested at the National Institute of Standards and Technology (NIST) have researchers seeing stars. In a recent paper, NIST scientists used surface-enhanced Raman spectroscopy (SERS) to demonstrate that gold nanostars exhibit optical qualities that make them superior for chemical and biological sensing and imaging. These uniquely shaped nanoparticles may one day be used in a range of applications from disease diagnostics to contraband identification.

SERS relies on metallic nanoparticles, most commonly gold and silver, to amplify signals from molecules present in only trace quantities. For these types of experiments, scientists shine laser light on an aqueous solution containing the nanoparticles and the molecule of interest and monitor the scattered light. The detailed characteristics of both the molecule and the nanoparticle affect the strength of scattered light, which contains an identifying fingerprint for the molecule known as its vibrational signature. With nanoparticles amplifying the signature, it is possible to detect a very low concentration of molecules in a solution.

The NIST team tested the optical properties of the nanostars using two target molecules, 2-mercaptopyridine and crystal violet. These molecules were selected because of their structural similarity to biological molecules and their large number of delocalized electrons, a characteristic that lends itself to SERS. NIST researchers found that the Raman signal of 2-mercaptopyridine was 100,000 stronger when nanostars were present in the solution. The stars were also shown to be particularly capable of enhancing the signature of crystal violet, delivering a signal about 10 times stronger than the previous winner, nanorods. Both the nanostars and the nanorods outperformed the nanospheres commonly used for Raman enhancement.

NIST physicist Angela Hight Walker and her team perfected the process for making gold nanostars, building them from the bottom-up using surface alterations to manipulate their growth and control their shape. Once suspended in a solution, the team guided the nanostars to gather together to form multiple “hot spots,” where the enhancement is dramatically larger than for a single nanostar.

According to Hight Walker, the fact that they can now be created en masse and have desirable optical properties should prompt researchers to examine their possible applications, perhaps eventually making them the stars of the nanoworld.


Story Source:

The above story is based on materials provided by National Institute of Standards and Technology. Note: Materials may be edited for content and length.


Journal Reference:

  1. Nalbant Esenturk et al. Surface-enhanced Raman scattering spectroscopy via gold nanostars. Journal of Raman Spectroscopy, September 24, 2008; DOI: 10.1002/jrs.2084

Cite This Page:

National Institute of Standards and Technology. "Gold Nanostars Outshine The Competition." ScienceDaily. ScienceDaily, 20 October 2008. <www.sciencedaily.com/releases/2008/10/081015183504.htm>.
National Institute of Standards and Technology. (2008, October 20). Gold Nanostars Outshine The Competition. ScienceDaily. Retrieved April 18, 2014 from www.sciencedaily.com/releases/2008/10/081015183504.htm
National Institute of Standards and Technology. "Gold Nanostars Outshine The Competition." ScienceDaily. www.sciencedaily.com/releases/2008/10/081015183504.htm (accessed April 18, 2014).

Share This



More Matter & Energy News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Small Reactors Could Be Future of Nuclear Energy

Small Reactors Could Be Future of Nuclear Energy

AP (Apr. 17, 2014) After the Fukushima nuclear disaster, the industry fell under intense scrutiny. Now, small underground nuclear power plants are being considered as the possible future of the nuclear energy. (April 17) Video provided by AP
Powered by NewsLook.com
Horseless Carriage Introduced at NY Auto Show

Horseless Carriage Introduced at NY Auto Show

AP (Apr. 17, 2014) An electric car that proponents hope will replace horse-drawn carriages in New York City has also been revealed at the auto show. (Apr. 17) Video provided by AP
Powered by NewsLook.com
Honda's New ASIMO Robot, More Human-Like Than Ever

Honda's New ASIMO Robot, More Human-Like Than Ever

AFP (Apr. 17, 2014) It walks and runs, even up and down stairs. It can open a bottle and serve a drink, and politely tries to shake hands with a stranger. Meet the latest ASIMO, Honda's humanoid robot. Duration: 00:54 Video provided by AFP
Powered by NewsLook.com
German Researchers Crack Samsung's Fingerprint Scanner

German Researchers Crack Samsung's Fingerprint Scanner

Newsy (Apr. 16, 2014) German researchers have used a fake fingerprint made from glue to bypass the fingerprint security system on Samsung's new Galaxy S5 smartphone. Video provided by Newsy
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:
from the past week

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