Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Carbon nanotubes found to fluoresce

30.07.2002


Optical properties could prove useful in biomedical, nanoelectronic applications

Add fluorescence to the growing list of unique physical properties associated with carbon nanotubes -- the ultrasmall, ultrastrong wunderkind of the fullerene family of carbon molecules.

In research detailed in the current issue of Science magazine, a team of Rice University chemists led by fullerene discoverer and Nobel laureate Richard Smalley describes the first observations of fluorescence in carbon nanotubes. Fluorescence occurs when a substance absorbs one wavelength of light and emits a different wavelength in response. The Rice experiments, conducted by Smalley’s group and the photophysics research team of chemist R. Bruce Weisman, found that nanotubes absorbed and gave off light in the near-infrared spectrum, which could prove useful in biomedical and nanoelectronics applications.



"Some of the most sophisticated biomedical tests today -- such as MRI exams -- cannot be performed in a doctor’s office because the equipment too large and too expensive to operate," said Smalley, University Professor at Rice. "Because nothing in the human body fluoresces in the near-infrared spectrum, and human tissue is fairly transparent at that spectrum, one can envision a test apparatus based on this technology that would be as inexpensive and simple to use as ultrasound."

Optical biosensors based on nanotubes could also be targeted to seek out specific targets within the body, such as tumor cells or inflamed tissues. Targeting would be achieved by wrapping the tubes with a protein that would bind only to the target cells. Since nanotubes fluoresce with a single wavelength of light, and different diameter nanotubes give off different wavelengths, it may be possible to tailor different sizes of tubes to seek specific targets, and thus diagnose multiple maladies in a single test using a cocktail of nanotubes.

Carbon nanotubes are a member of the fullerene family of carbon molecules, a third molecular form of carbon that is distinct from diamond and graphite. The discovery of fullerenes in 1985 earned Smalley a share of the Nobel Prize.

Like all fullerenes, carbon nanotubes are extraordinarily stable and almost impervious to radiation and chemical destruction. They’re small enough to migrate through the walls of cells, conduct electricity as well as copper, conduct heat as well as diamond and are 100 times stronger than steel at one-sixth the weight.

Much of Smalley’s current research involves bridging the gap between "wet" nanotechnology -- the molecular, biochemical machinery of life -- and "dry," insoluble nanomaterials like fullerenes. Toward that end, Smalley’s lab has churned out dozens of varieties of soluble fullerenes by wrapping nanotubes in various polymers, including proteins, starches and DNA.

In the fluorescence experiments, Smalley and Weisman’s teams observed the effect only in nanotubes that were untangled and isolated from neighboring tubes. Researchers bombarded clumps of nanotubes with high-frequency sound waves to separate them, and they encased each individual tube in a molecule of sodium dodecylsulfate in order to isolate it from its neighbors. Fluorescence was observed in both plain and polymer-wrapped nanotubes.

In addition to biomedical applications, the fluorescence research could prove useful in the field of nanoelectronics because it confirms that nanotubes are direct band-gap semiconductors, which means they emit light in a way that could be useful for engineers in the fiber optics industry.


The Rice research team included Michael O’Connell, Sergei Bachilo, Chad Huffman, Valerie Moore, Michael Strano, Erik Haroz, Kristy Rialon, Peter Boul, William Noon, Carter Kittrell, Jianpeng Ma and Robert H. Hauge. The research was funded by the National Science Foundation and the Robert A. Welch Foundation.

Jade Boyd | EurekAlert!
Further information:
http://chico.rice.edu/

More articles from Life Sciences:

nachricht New switch decides between genome repair and death of cells
27.09.2016 | University of Cologne - Universität zu Köln

nachricht A blue stoplight to prevent runaway photosynthesis
27.09.2016 | National Institute for Basic Biology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First quantum photonic circuit with electrically driven light source

Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

Im Focus: Launch of New Industry Working Group for Process Control in Laser Material Processing

At AKL’16, the International Laser Technology Congress held in May this year, interest in the topic of process control was greater than expected. Appropriately, the event was also used to launch the Industry Working Group for Process Control in Laser Material Processing. The group provides a forum for representatives from industry and research to initiate pre-competitive projects and discuss issues such as standards, potential cost savings and feasibility.

In the age of industry 4.0, laser technology is firmly established within manufacturing. A wide variety of laser techniques – from USP ablation and additive...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Laser use for neurosurgery and biofabrication - LaserForum 2016 focuses on medical technology

27.09.2016 | Event News

Experts from industry and academia discuss the future mobile telecommunications standard 5G

23.09.2016 | Event News

ICPE in Graz for the seventh time

20.09.2016 | Event News

 
Latest News

New switch decides between genome repair and death of cells

27.09.2016 | Life Sciences

Nanotechnology for energy materials: Electrodes like leaf veins

27.09.2016 | Physics and Astronomy

‘Missing link’ found in the development of bioelectronic medicines

27.09.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>