Featured Research

from universities, journals, and other organizations

Surface Plasmon Resonances Of Metal Nanoparticles In Array Can Have Narrower Spectral Widths

Date:
November 14, 2008
Source:
Harvard University
Summary:
Researchers at the Harvard School of Engineering and Applied Sciences have demonstrated experimentally and theoretically that the surface plasmon resonances of metal nanoparticles in a periodic array can have considerably narrower spectral widths than those of isolated metal nanoparticles. Further, as the optical fields are significantly more intense in a periodic array, the method could improve the sensitivity of detecting molecules at low concentrations.

Researchers at the Harvard School of Engineering and Applied Sciences (SEAS) have demonstrated experimentally and theoretically that the surface plasmon resonances of metal nanoparticles in a periodic array can have considerably narrower spectral widths than those of isolated metal nanoparticles.

Further, as the optical fields are significantly more intense in a periodic array, the method could improve the sensitivity of detecting molecules at low concentrations.

While researchers have known that a group of nanoparticles could be used to increase signal levels for sensor applications, the electromagnetic interactions between the particles have often been overlooked. A team led by Ken Crozier, John L. Loeb Associate Professor of the Natural Sciences at SEAS, showed that by spacing a nanoparticle array appropriately, the interactions between nanoparticles can be optimized.

The study, published in the November 3 issue of Applied Physics Letters, was carried out by Yizhuo Chu, Ethan Schonbrun and Tian Yang under the direction of Professor Crozier, all of SEAS. "We used numerical electromagnetic simulations to design nanoparticle arrays exhibiting narrow surface plasmon resonance peaks and intense optical fields, and checked our predictions experimentally," said Crozier.

To do so, Crozier and his team fabricated the nanoparticle arrays using electron beam lithography on glass substrates. By measuring the optical transmission of collimated beams of white light through the arrays, the team found that their experimental results confirmed their original theoretical predictions of sharp plasmon resonance peaks.

"The narrow peaks occur when the product of the nanoparticle spacing and the refractive index of the surrounding medium approximately matches the plasmon resonance wavelength of a single nanoparticle," explained Crozier.

Over the past several years, Crozier and his colleagues have helped to advance the field of plasmonics, harnessing its ability to confine electromagnetic fields to deep sub-wavelength dimensions for spectroscopy, sensing and optical manipulation. The larger field enhancement demonstrated in their latest finding could be important for further refining surface enhanced Raman spectroscopy and for improving biosensors.

The work was supported by the National Science Foundation, the Defense Advanced Research Projects Agency, the Charles Stark Draper Laboratory, and the Harvard Nanoscale Science and Engineering Center.


Story Source:

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


Cite This Page:

Harvard University. "Surface Plasmon Resonances Of Metal Nanoparticles In Array Can Have Narrower Spectral Widths." ScienceDaily. ScienceDaily, 14 November 2008. <www.sciencedaily.com/releases/2008/11/081114101749.htm>.
Harvard University. (2008, November 14). Surface Plasmon Resonances Of Metal Nanoparticles In Array Can Have Narrower Spectral Widths. ScienceDaily. Retrieved September 3, 2014 from www.sciencedaily.com/releases/2008/11/081114101749.htm
Harvard University. "Surface Plasmon Resonances Of Metal Nanoparticles In Array Can Have Narrower Spectral Widths." ScienceDaily. www.sciencedaily.com/releases/2008/11/081114101749.htm (accessed September 3, 2014).

Share This



More Matter & Energy News

Wednesday, September 3, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Halliburton Reaches $1B Gulf Spill Settlement

Halliburton Reaches $1B Gulf Spill Settlement

AP (Sep. 2, 2014) Halliburton's agreement to pay more than $1 billion to settle numerous claims involving the 2010 BP oil spill could be a way to diminish years of costly litigation. A federal judge still has to approve the settlement. (Sept. 2) Video provided by AP
Powered by NewsLook.com
Google Teases India Event, Possible Android One Reveal

Google Teases India Event, Possible Android One Reveal

Newsy (Sep. 1, 2014) Google has announced a Sept. 15 event in India during which they're expected to reveal their Android One phones. Video provided by Newsy
Powered by NewsLook.com
Australian Airlines Relax Phone Ban Too

Australian Airlines Relax Phone Ban Too

Reuters - Business Video Online (Aug. 26, 2014) Qantas and Virgin say passengers can use their smartphones and tablets throughout flights after a regulator relaxed a ban on electronic devices during take-off and landing. As Hayley Platt reports the move comes as the two domestic rivals are expected to post annual net losses later this week. Video provided by Reuters
Powered by NewsLook.com
Hurricane Marie Brings Big Waves to California Coast

Hurricane Marie Brings Big Waves to California Coast

Reuters - US Online Video (Aug. 26, 2014) Huge waves generated by Hurricane Marie hit the Southern California coast. Rough Cut (no reporter narration). Video provided by Reuters
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