Detection of DNA on nanotubes offers new sensing, sequencing technologies

February 20, 2006
Michael Strano
Michael Strano, professor of chemical and biomolecular engineering, and his students have found that DNA-wrapped nanotubes can be used to target specific DNA sequences. Photo by L. Brian Stauffer

Researchers at the University of Illinois at Urbana-Champaign who recently reported that DNA-wrapped carbon nanotubes could serve as sensors in living cells now say the tiny tubes can be used to target specific DNA sequences. Potential applications for the new sensors range from rapid detection of hazardous biological agents to simpler and more efficient forensic identification.

In the Jan. 27 issue of the journal Science, chemical and biomolecular engineering professor Michael Strano and his students reported that single-walled carbon nanotubes coated with DNA could be placed in living cells and detect trace amounts of harmful contaminants. In a paper accepted for publication in the journal Nano Letters, and posted on its Web site, the researchers report they have taken the technique a significant step further.

“We have successfully demonstrated the optical detection of selective DNA hybridization on the surface of a nanotube,” said Strano, who is also a researcher at the Beckman Institute for Advanced Science and Technology and at the university’s Micro and Nanotechnology Laboratory. “This work opens possibilities for new types of nanotube-based sensing and sequencing technologies.”

In its natural state, DNA is in the double stranded form, consisting of two complementary strands, each resembling the side of a ladder and having a specific sequence of nucleotide bases as rungs. Hybridization refers to the spontaneous binding of two complementary strands through base pair matching.

By wrapping one strand of DNA around the surface of a carbon nanotube, the researchers can create a sensor that is targeted for a particular piece of complementary DNA. When the complementary DNA then binds to the DNA probe, the nanotube’s natural near-infrared fluorescence is shifted slightly, and can readily be detected.

“The optical detection of specific DNA sequences through hybridization with a complementary DNA probe has many potential applications in medicine, microbiology and environmental science,” said Esther Jeng, a graduate student at Illinois and the paper’s lead author. “For example, this system could be used in genomic screening to detect sequences that encode for genetic disorders, and that are precursors to diseases such as breast cancer.”

“Optical detection allows for passive sensing of hybridization, meaning there is no need to pass voltage or current through the system,” Jeng said. “Furthermore, optics yield high-resolution signals and require a relatively simple setup. And, because our detection setup is in solution, we can sense in a natural biological environment.”

Co-authors of the paper with Strano and Jeng are undergraduate students Joseph Gastala, Anthonie Moll and Amanda Roy. The work was funded by the National Science Foundation.

Source: University of Illinois at Urbana-Champaign

Explore further: Science on the surface of a comet

Related Stories

Science on the surface of a comet

July 31, 2015

Complex molecules that could be key building blocks of life, the daily rise and fall of temperature, and an assessment of the surface properties and internal structure of the comet are just some of the highlights of the first ...

A controversial theory of olfaction deemed implausible

June 5, 2015

Humans can discriminate tens of thousands of odors. While we may take our sense of smell for granted, it adds immeasurably to our quality of life: the aroma of freshly brewed coffee; the invigorating smell of an ocean breeze ...

Responsive material could be the 'golden ticket' of sensing

January 7, 2015

Researchers from the University of Cambridge have developed a new self-assembled material, which, by changing its shape, can amplify small variations in temperature and concentration of biomolecules, making them easier to ...

Recommended for you

Magnetism at nanoscale

August 3, 2015

As the demand grows for ever smaller, smarter electronics, so does the demand for understanding materials' behavior at ever smaller scales. Physicists at the U.S. Department of Energy's Ames Laboratory are building a unique ...

How the finch changes its tune

August 3, 2015

Like top musicians, songbirds train from a young age to weed out errors and trim variability from their songs, ultimately becoming consistent and reliable performers. But as with human musicians, even the best are not machines. ...

Study calculates the speed of ice formation

August 3, 2015

Researchers at Princeton University have for the first time directly calculated the rate at which water crystallizes into ice in a realistic computer model of water molecules. The simulations, which were carried out on supercomputers, ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.