Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Golden Bowties

Abstract:
Nanoantenna can compress ordinary light waves into an intense optical spot only 20 nanometers wide

Gold bowties may shed light on molecules and other nano-sized objects

August 30, 2005

One of the great challenges in the field of nanotechnology is optical imaging - specifically, how to design a microscope that produces high-resolution images of the nano-sized objects that researchers are trying to study. For example, a typical DNA molecule is only about three nanometers wide - so tiny that the contours of its surface are obscured by light waves, which are hundreds of nanometers long.

Now, researchers from Stanford University have greatly improved the optical mismatch between nanoscale objects and light by creating the "bowtie nanoantenna," a device 400 times smaller than the width of a human hair that can compress ordinary light waves into an intense optical spot only 20 nanometers wide. These miniature spotlights may one day allow researchers to produce the first detailed images of proteins, DNA molecules and synthetic nano-objects, such carbon nanotube bundles.

"One of our goals is to build a microscope with bowtie antennas that we can scan over a single molecule," says W.E. Moerner, the Harry S. Mosher Professor of Chemistry at Stanford. He and his Stanford colleagues introduced the bowtie nanoantenna earlier this year in a study published in the journal Physical Review Letters that was co-authored by postdoctoral fellow P. James Schuck and graduate student David Fromm in the Department of Chemistry, and Professor Emeritus Gordon Kino and graduate student Arvind Sundaramurthy in the Department of Electrical Engineering.

Golden bowties

The bowtie nanoantenna consists of two triangular pieces of gold, each about 75 nanometers long, whose tips face each other in the shape of a miniature bowtie. The device operates like an antenna for a radio receiver, but instead of amplifying radio waves, the bowtie takes energy from an 830-nanometer beam of near-infrared light and squeezes it into a 20-nanometer gap that separates the two gold triangles. The result is a concentrated speck of light that is a thousand times more intense than the incoming near-infrared beam.

"What you end up with is a very small optical spot that you could scan to make detailed images of molecules and other nano-particles," says Kino, the W.M. Keck Foundation Professor of Electrical Engineering, Emeritus. "Normally we use lenses to focus, but it's not possible to resolve detail in objects smaller than one-half the wavelength of light."

Because the shortest wavelength of visible light is 400 nanometers, a conventional microscope cannot resolve objects 200 nanometers or smaller. "But the bowtie antenna produces an optical spot that's 20-nanometers wide, so we're improving the resolution by a factor of 10," Kino says.

Polymers and sensors

In addition to nano-scale optical imaging, Moerner says that bowties may be useful in photopolymerization, a process that uses light to create synthetic compounds (polymers), which researchers can use to trap nano-particles and place them in specific locations. "It's difficult to put molecules and crystals exactly where you want them when you're working at a nano-scale," Schuck explains.

Bowties also may have applications in Raman spectroscopy, a technique that allows scientists to identify individual molecules by measuring the vibrational energy the molecule emits when exposed to light. "It's analogous to fingerprinting," Schuck explains. "Each molecule has a unique vibrational energy, and bowties have a potential use as biological or chemical sensors that can differentiate molecules."

The Stanford team plans to explore these and other practical applications of bowtie nanoantennas in future experiments. On Aug. 30, Moerner will discuss bowties and other developments in the field of nanophotonics at the annual meeting of the American Chemical Society in Washington, D.C.

####


Professor W.E. Moerner will discuss nanophotonics and single-molecule biophysics at the annual meeting of the American Chemical Society in Washington, D.C., on Aug. 30 at 8:30 a.m. For more information, visit the ACS website at http://www.chemistry.org.

Media Contacts:
Mark Shwartz
News Service
(650) 723-9296
mshwartz@stanford.edu

Relevant URL's:
http://www.stanford.edu/group/moerner
http://snf.stanford.edu
http://www.chemistry.org

Copyright © Stanford 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 News Press

Possible Futures

Nanotechnology in Medical Devices Market is expected to reach $8.5 Billion by 2019 March 25th, 2015

Nanotechnology Enabled Drug Delivery to Influence Future Diagnosis and Treatments of Diseases March 21st, 2015

Nanocomposites Market Growth, Industry Outlook To 2020 by Grand View Research, Inc. March 21st, 2015

Nanotechnology Drug Delivery Market in the US 2012-2016 : Latest Report Available by Radiant Insights, Inc March 16th, 2015

Announcements

A first glimpse inside a macroscopic quantum state March 28th, 2015

DFG to Establish One Clinical Research Unit and Five Research Units: New Projects to Investigate Complications in Pregnancy, Particle Physics, Nanoparticles, Implants and Transport Planning / Approximately 13 Million Euros in Funding for an Initial Three-Year Period March 28th, 2015

Designer's toolkit for dynamic DNA nanomachines: Arm-waving nanorobot signals new flexibility in DNA origami March 27th, 2015

Using magnetic fields to understand high-temperature superconductivity: Los Alamos explores experimental path to potential 'next theory of superconductivity' March 27th, 2015

Tools

LAMDAMAP 2015 hosted by the University March 26th, 2015

FEI Technology Award of the German Neuroscience Society Goes to Benjamin Judkewitz of the University of Berlin: Bi-annual award honors excellence in brain research during the German Neuroscience Society’s Annual Meeting, held 18-21 March 2015 March 26th, 2015

Square ice filling for a graphene sandwich March 26th, 2015

Nanorobotic agents open the blood-brain barrier, offering hope for new brain treatments March 25th, 2015

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







© Copyright 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE