Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button

Home > Press > UConn chemists find secret to increasing luminescence efficiency of carbon nanotubes

Abstract:
Breakthrough procedure has potential applications in medical imaging, homeland security, biological sensors

UConn chemists find secret to increasing luminescence efficiency of carbon nanotubes

Storrs, CT | Posted on March 6th, 2009

Chemists at the University of Connecticut have found a way to greatly increase the luminescence efficiency of single-walled carbon nanotubes, a discovery that could have significant applications in medical imaging and other areas.

Increasing the luminescence efficiency of carbon nanotubes may someday make it possible for doctors to inject patients with microscopic nanotubes to detect tumors, arterial blockages and other internal problems. Rather than relying on potentially harmful x-rays or the use of radioactive dyes, physicians could simply scan patients with an infrared light that would capture a very sharp resolution of the luminescence of the nanotubes in problem areas.

UConn's process of increasing the luminescence efficiency of single-walled carbon nanotubes will be featured in Science magazine on Friday, March 6, 2009. The research was performed in the Nanomaterials Optoelectronics Laboratory at the Institute of Materials Science at the University of Connecticut, in Storrs, CT. A patent for the process is pending.

University of Connecticut Chemist Fotios Papadimitrakopoulos describes the discovery as a major breakthrough and one of the most significant discoveries in his 10 years of working with single-walled carbon nanotubes. Assisting Papadimitrakopoulos with the research were Polymer Program graduate student Sang-Yong Ju (now a researcher at Cornell University) and William P. Kopcha, a former Chemistry undergraduate assistant in the College of Liberal Arts and Sciences who is now a first-year graduate student at UConn.

Although carbon is used in many diverse applications, scientists have long been stymied by the element's limited ability to emit light. The best scientists have been able to do with solution-suspended carbon nanotubes was to raise their luminescence efficiency to about one-half of one percent, which is extremely low compared to other materials, such as quantum dots and quantum rods.

By tightly wrapping a chemical 'sleeve' around a single-walled carbon nanotube, Papadimitrakopoulos and his research team were able to reduce exterior defects caused by chemically absorbed oxygen molecules.

This process can best be explained by imagining sliding a small tube into a slightly larger diameter tube, Papadimitrakopoulos says. In order for this to happen, all deposits or protrusions on the smaller tube have to be removed before the tube is allowed to slip into the slightly larger diameter tube. What is most fascinating with carbon nanotubes however, Papadimitrakopoulos says, is the fact that in this case the larger tube is not as rigid as the first tube (i.e. carbon nanotube) but is rather formed by a chemical "sleeve" comprised of a synthetic derivative of flavin (an analog of vitamin B2) that adsorbs and self organizes onto a conformal tube.
Papadimitrakopoulos claims that this process of self-assembly is unique in that it not only forms a new structure but also actively "cleans" the surface of the underlying nanotube. It is that active cleaning of the nanotube surface that allows the nanotube to achieve luminescence efficiency to as high as 20 percent.

NOTE: To see a QuickTime animation of how a single-walled carbon nanotube is wrapped with the synthetic flavin derivative to increase its luminescence go to: www.ims.uconn.edu/~papadim/research.htm

"The nanotube is the smallest tube on earth and we have found a sleeve to put over it," Papadimitrakopoulos says. "This is the first time that a nanotube was found to emit with as much as 20 percent luminescence efficiency."

Papadimitrakopoulos has been working closely with the UConn Center for Science and Technology Commercialization (CSTC) in transferring his advances in research into the realm of patents, licenses and corporate partnerships. The CSTC was created several years ago as a way to help expand Connecticut's innovation-based economy and to help create new businesses and jobs around new ideas.

This is the second major nanotube discovery at UConn by Papadimitrakopoulos in the past two years. Last year, Papadimitrakopoulos and Sang-Young Ju, along with other UConn researchers, patented a way to isolate certain carbon nanotubes from others by seamlessly wrapping a form of vitamin B2 around the nanotubes. It was out of that research that Papadimitrakopoulos and Sang-Yong Ju began wrapping nanotubes with helical assemblies and probing their luminescence properties.

The more luminescent the nanotube, the brighter it appears under infrared irradiation or by electrical excitation (such as that provided by a light-emitting diode or LED). A number of important applications may be possible as a result of this research, Papadimitrakopoulos says. Carbon nanotube emissions are not only extremely sharp, but they also appear in a spectral region where minimal absorption or scattering takes place by soft tissue. Moreover, carbon nanotubes display superb photo bleaching stability and are ideally suited for near-infrared emitters, making them appropriate for applications in medicine and homeland security as bio-reporting agents and nano-sized beacons. Carbon nanotube luminescence also has important applications in nano-scaled LEDs and photo detectors, which can readily integrate with silicon-based technology. This provides an enormous repertoire for nanotube use in advanced fiber optics components, infrared light modulators, and biological sensors, where multiple applications are possible due to the nanotube's flavin-based (vitamin B2) helical wrapping.

A complete copy of the research article that will appear in Science magazine on Friday, March 6, will be available after 2 p.m. on Thursday, March 5 at: www.sciencemag.org/sciencexpress/recent.dtl

More information about the University of Connecticut's Nanomaterials Optoelectronics Laboratory can be found at: chemistry.uconn.edu/papadim/index.htm

####

For more information, please click here

Contacts:
Colin Poitras

860-486-4656

Additional Contact Information:
Fotios Papadimitrakopoulos
Professor of Chemistry
Associate Director
Institute of Materials Science
University of Connecticut
Tel: (860)-486-3447
Fax: (860)-486-4745

Copyright © University of Connecticut

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

News and information

Making magnets flip like cats at room temperature: Heusler alloy NiMnSb could prove valuable as a new material for digital information processing and storage July 25th, 2016

An accelerated pipeline to open materials research: ORNL workflow system unites imaging, algorithms, and HPC to advance materials discovery and design July 24th, 2016

Russian physicists discover a new approach for building quantum computers: Physicists find a way of 'bundling together' multiple elements of a quantum computer July 24th, 2016

A 'smart dress' for oil-degrading bacteria July 24th, 2016

Imaging

An accelerated pipeline to open materials research: ORNL workflow system unites imaging, algorithms, and HPC to advance materials discovery and design July 24th, 2016

New superconducting coil improves MRI performance: UH-led research offers higher resolution, shorter scan time July 23rd, 2016

The birth of quantum holography: Making holograms of single light particles! July 21st, 2016

Graphene photodetectors: Thinking outside the 2-D box July 21st, 2016

A glimpse inside the atom: Using electron microscopes, it is possible to image individual atoms July 20th, 2016

Chemistry

New reaction for the synthesis of nanostructures July 21st, 2016

Nanotubes/Buckyballs/Fullerenes

Easier, faster, cheaper: A full-filling approach to making nanotubes of consistent quality: Approach opens a straightforward route for engineering the properties of single-wall carbon nanotubes July 19th, 2016

Sensing trouble: A new way to detect hidden damage in bridges, roads: University of Delaware engineers devise new method for monitoring structural health July 8th, 2016

Wireless, wearable toxic-gas detector: Inexpensive sensors could be worn by soldiers to detect hazardous chemical agents July 4th, 2016

Nanotubes' 'stuffing' as is: A scientist from the Lomonosov Moscow State University studied the types of carbon nanotubes' 'stuffing' June 2nd, 2016

Sensors

Electron 'spin control' of levitated nanodiamonds could bring advances in sensors, quantum information processing July 20th, 2016

Easier, faster, cheaper: A full-filling approach to making nanotubes of consistent quality: Approach opens a straightforward route for engineering the properties of single-wall carbon nanotubes July 19th, 2016

Researchers invent 'smart' thread that collects diagnostic data when sutured into tissue: Advances could pave way for new generation of implantable and wearable diagnostics July 18th, 2016

UNIST engineers octopus-inspired smart adhesive pads July 15th, 2016

Discoveries

Making magnets flip like cats at room temperature: Heusler alloy NiMnSb could prove valuable as a new material for digital information processing and storage July 25th, 2016

An accelerated pipeline to open materials research: ORNL workflow system unites imaging, algorithms, and HPC to advance materials discovery and design July 24th, 2016

Russian physicists discover a new approach for building quantum computers: Physicists find a way of 'bundling together' multiple elements of a quantum computer July 24th, 2016

A 'smart dress' for oil-degrading bacteria July 24th, 2016

Announcements

Making magnets flip like cats at room temperature: Heusler alloy NiMnSb could prove valuable as a new material for digital information processing and storage July 25th, 2016

An accelerated pipeline to open materials research: ORNL workflow system unites imaging, algorithms, and HPC to advance materials discovery and design July 24th, 2016

Russian physicists discover a new approach for building quantum computers: Physicists find a way of 'bundling together' multiple elements of a quantum computer July 24th, 2016

A 'smart dress' for oil-degrading bacteria July 24th, 2016

Homeland Security

New method can identify chemical warfare agents more easily: The method could help governments protect people from horrifying toxic effects July 15th, 2016

Researchers harness DNA as the engine of super-efficient nanomachine: New platform detects traces of everything from bacteria to viruses, cocaine and metals July 10th, 2016

Electronic nose smells pesticides and nerve gas July 6th, 2016

Wireless, wearable toxic-gas detector: Inexpensive sensors could be worn by soldiers to detect hazardous chemical agents July 4th, 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