The work, which is the first application of a whole new class of biological sensors, was funded by the National Science Foundation (NSF) and announced December 12 in the online edition of the journal Nature Materials.
Principal investigator Michael Strano, a professor of chemical and biomolecular engineering at Illinois, explains that the new sensors are based on single-walled carbon nanotubes: cylindrical molecules whose sides are formed from a lattice of carbon atoms. The idea is to exploit the nanotubes' ability to fluoresce, or glow, when illuminated by certain wavelengths of infrared light-"a region of the spectrum where human tissue and biological fluids are particularly transparent," says Strano.
To make a sensor, Strano and his collaborators first coat the nanotubes with a "molecular sheath": a one-molecule-thick layer of compounds that react strongly with a particular chemical-in this case, glucose. The mix of compounds is chosen so that the reaction also changes the nanotubes' fluorescent response. Then the researchers load the coated nanotubes into a needle-thin capillary tube that can safely be implanted into the body. The capillary keeps the nanotubes from directly touching living cells but still allows glucose to enter.
The Illinois researchers tested their glucose sensor by inserting it into a human tissue sample. Then they illuminated the sample with an infrared laser and verified that the strength of the fluorescence from the buried sensor was directly related to the glucose concentrations in the tissue.
For more information see: UIUC Press Release: http://www.news.uiuc.edu/news/04/1213strano.html
Program contact: Glenn Schrader, NSF, 703-292-8371, firstname.lastname@example.org
The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering, with an annual budget of nearly $5.58 billion. NSF funds reach all 50 states through grants to nearly 2,000 universities and institutions. Each year, NSF receives about 40,000 competitive requests for funding, and makes about 11,000 new funding awards. The NSF also awards over $200 million in professional and service contracts yearly.
Receive official NSF news electronically through the e-mail delivery system, NSFnews. To subscribe, send an e-mail message to email@example.com. In the body of the message, type "subscribe nsfnews" and then type your name. (Ex.: "subscribe nsfnews John Smith")
Useful NSF Web Sites:
NSF Home Page: http://www.nsf.gov
News Highlights: http://www.nsf.gov/od/lpa
Science Statistics: http://www.nsf.gov/sbe/srs/stats.htm
Awards Searches: http://www.fastlane.nsf.gov/a6/A6Start.htm