Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Nanobelts support manipulation of light: Rice University lab discovers tiny gold bars have strong plasmonic properties

Gold nanobelts less than 100 nanometers wide, seen under a dark-field microscope, scatter light in specific colors depending on their cross-sectional aspect ratio -- width divided by height. The belts could be useful in biomedical and sensing applications.
(Credit Hafner Lab/Rice University)
Gold nanobelts less than 100 nanometers wide, seen under a dark-field microscope, scatter light in specific colors depending on their cross-sectional aspect ratio -- width divided by height. The belts could be useful in biomedical and sensing applications.

(Credit Hafner Lab/Rice University)

Abstract:
They look like 2-by-4s, but the materials being created in a Rice University lab are more suited to construction with light.

Researcher Jason Hafner calls them "nanobelts," microscopic strips of gold that could become part of highly tunable sensors or nanomedical devices.

Hafner, an associate professor of physics and astronomy and of chemistry, and his colleagues reported their discovery online this week in the American Chemical Society journal Nano Letters.

Nanobelts support manipulation of light: Rice University lab discovers tiny gold bars have strong plasmonic properties

Houston, TX | Posted on October 13th, 2011

Nanobelts represent a unique way to manipulate light at the microscopic scale. They join smaller nanoparticles like gold nanorods and nanoshells that can be tuned to absorb light strongly at certain wavelengths and then steer the light around or emit it in specific directions.

The effect is due to surface plasmons, which occur when free electrons in a metal or doped dielectric interact strongly with light. When prompted by a laser, the sun or other energy source, they oscillate like ripples on a pond and re-emit energy either as light or heat. They are the focus of much research for their potential benefits in biomedical applications, molecular sensing and microelectronics.

Nanobelts are unique because the plasmonic waves occur across their width, not along their length, Hafner said. "My intuition says that isn't likely. Why would you get a sharp resonance in the short direction when the electrons can go long? But that's what happens."

Nanobelts scatter light at a particular wavelength (or color), depending on the aspect ratio of their cross sections - width divided by height. That makes them highly tunable, Hafner said, by controlling that aspect ratio.

He was quick to point out his lab didn't make the first gold nanobelts. "We first searched the literature for a way to make a structure that might have a sharp resonance, because we wanted a large field enhancement," he said, referring to a technique he uses to characterize the effect of local environment on nanoparticle emissions.

The team found what it was looking for in a 2008 Langmuir paper by a Peking University team. "They made the same structure, but they didn't look too closely at the optical properties," he said. "They did beautiful work to discover the crystal structure and the growth direction, and they demonstrated the use of nanobelts in catalysis.

"As soon as we looked at the sample in a dark-field microscope, we instantly saw colors. We just couldn't believe it."

Hafner, a 1996 Rice alum who studied with the late Nobel laureate Richard Smalley, said growing nanobelts is a slow process. It takes 12 hours to synthesize a batch of nanobelts, which appear to grow in clusters from a central nucleus.

The team has grown nanobelts up to 100 microns long that range from basic square cross sections -- 25-by-25 nanometers -- to flattened, at 100 nanometers wide by 17 nanometers high. They found that the flatter the nanobelt, the more the scattered light shifted toward red.

"People have studied electrons moving the long way in these kinds of materials, but when they get too long the resonances detune out of the visible and the peaks become so broad that there's no sharp resonance anymore," Hafner said. "We're going across the nanobelt, so length doesn't matter. The nanobelt could be a meter long and still show sharp plasmon resonance."

Co-authors of the paper are graduate students Lindsey Anderson, Courtney Payne and Yu-Rong Zhen and Peter Nordlander, a professor of physics and astronomy and in electrical and computer engineering.

Support for the research came from the National Science Foundation and the Robert A. Welch Foundation.

####

About Rice University
Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is known for its "unconventional wisdom." With 3,485 undergraduates and 2,275 graduate students, Rice's undergraduate student-to-faculty ratio is less than 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice has been ranked No. 1 for best quality of life multiple times by the Princeton Review and No. 4 for "best value" among private universities by Kiplinger's Personal Finance. To read "What they're saying about Rice," go to www.rice.edu/nationalmedia/Rice.pdf.

For more information, please click here

Contacts:
David Ruth
713-348-6327


Mike Williams
713-348-6728

Copyright © Rice University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Read the abstract at:

Related News Press

News and information

Creating a color printer that uses a colorless, non-toxic ink inspired by nature February 11th, 2016

SLAC X-ray laser turns crystal imperfections into better images of important biomolecules: New method could remove major obstacles to studying structures of complex biological machines February 11th, 2016

Nanoparticle reduces targeted cancer drug's toxicity February 11th, 2016

Cima NanoTech Debuts Large Interactive Touch Screens with European Customers at ISE 2016: For the first time in Europe, Cima NanoTech’s wide range of high performance, projected capacitive touch modules are showcased February 11th, 2016

Govt.-Legislation/Regulation/Funding/Policy

Creating a color printer that uses a colorless, non-toxic ink inspired by nature February 11th, 2016

SLAC X-ray laser turns crystal imperfections into better images of important biomolecules: New method could remove major obstacles to studying structures of complex biological machines February 11th, 2016

Composite Pipe Long Term Testing Facility February 10th, 2016

Scientists take nanoparticle snapshots February 10th, 2016

Nanomedicine

SLAC X-ray laser turns crystal imperfections into better images of important biomolecules: New method could remove major obstacles to studying structures of complex biological machines February 11th, 2016

Nanoparticle reduces targeted cancer drug's toxicity February 11th, 2016

Nanoparticle therapy that uses LDL and fish oil kills liver cancer cells February 9th, 2016

Leading bugs to the death chamber: A kinder face of cholesterol February 8th, 2016

Sensors

Scientists have put a high precision blood assay into a simple test strip: Researchers have developed a new biosensor test system based on magnetic nanoparticles February 3rd, 2016

Nanosheet growth technique could revolutionize nanomaterial production February 1st, 2016

New record in nanoelectronics at ultralow temperatures January 28th, 2016

NBC LEARN DEBUTS SIX-PART VIDEO SERIES, “NANOTECHNOLOGY: SUPER SMALL SCIENCE” Produced by NBC Learn in partnership with the National Science Foundation, and narrated by NBC News/MSNBC’s Kate Snow, series highlights leading research in nanotechnology January 25th, 2016

Discoveries

Creating a color printer that uses a colorless, non-toxic ink inspired by nature February 11th, 2016

SLAC X-ray laser turns crystal imperfections into better images of important biomolecules: New method could remove major obstacles to studying structures of complex biological machines February 11th, 2016

Nanoparticle reduces targeted cancer drug's toxicity February 11th, 2016

Chemical cages: New technique advances synthetic biology February 10th, 2016

Announcements

Creating a color printer that uses a colorless, non-toxic ink inspired by nature February 11th, 2016

SLAC X-ray laser turns crystal imperfections into better images of important biomolecules: New method could remove major obstacles to studying structures of complex biological machines February 11th, 2016

Nanoparticle reduces targeted cancer drug's toxicity February 11th, 2016

Cima NanoTech Debuts Large Interactive Touch Screens with European Customers at ISE 2016: For the first time in Europe, Cima NanoTech’s wide range of high performance, projected capacitive touch modules are showcased February 11th, 2016

Photonics/Optics/Lasers

Scientists take nanoparticle snapshots February 10th, 2016

Scientists create laser-activated superconductor February 8th, 2016

Nanoscale cavity strongly links quantum particles: Single photons can quickly modify individual electrons embedded in a semiconductor chip and vice versa February 8th, 2016

Organic crystals allow creating flexible electronic devices: The researchers from the Faculty of Physics of the Moscow State University have grown organic crystals that allow creating flexible electronic devices February 5th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic