University of Pittsburgh researcher Alexander Star and colleagues at California-based
company Nanomix, Inc., have developed devices made of carbon nanotubes that
can find mutations in genes causing hereditary diseases, they report in the
Jan. 16 issue of the journal Proceedings of the National Academy of Science.
This method is less expensive and takes less time than conventional techniques.
Carbon nanotubes are rolled-up sheets of graphite
only a few nanometers wide-about the width of a molecule
of DNA. The researchers used these nanotubes' electrical
properties to find a particular mutation in the gene
that causes hereditary hemochromatosis, a disease
in which too much iron accumulates in body tissues.
"The size compatibility between the detector and
the detected species-DNA molecules in this case-makes
this approach very attractive for further development
of label-free electronic methods," said Star, who
is an assistant professor of chemistry at Pitt.
Star and his colleagues at Nanomix also tested fluorescently
labeled DNA molecules in order to confirm that DNA
had attached to the nanotube surfaces and was subsequently
hybridized, or matched to its complementary DNA.
"We have found that electrical measurement of carbon
nanotube devices produce sensor results that are
comparable to state-of-the-art optical techniques," Star
He added, "The applications of our method for detection
of other, more serious genetic diseases can be seen."
Label-free electronic detection of DNA has several
advantages over state-of-the-art optical techniques,
including cost, time, and simplicity.
"Our technology can bring to market hand-held, field-ready
devices for genetic screening, as opposed to laboratory
methods using labor-intense labeling and sophisticated
optical equipment," Star said.
This research was partially supported by the National
Science Foundation's Small Business Innovation Research
Pitt has invested heavily in nanoscale research,
beginning with the establishment of its Institute
for NanoScience and Engineering (INSE), and continuing
with the NanoScale Fabrication and Characterization
Facility, which contains core technology such as
electron-beam lithography, transmission electron
microscopes, and a state-of-the-art cleanroom environment.
The INSE is an integrated, multidisciplinary organization
that brings coherence to the University's research
efforts and resources in the fields of nanoscale
science and engineering. For more information, visit www.nano.pitt.edu .
Contact: Karen Hoffmann
University of Pittsburgh