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Research
Nanotech Sensor Detects Toxins in Living Cells
US scientists have developed a tiny sensor that can detect small amounts of
cancer-causing toxins or trace the effectiveness of cancer drugs inside living
cells. The finding, reported in the journal Nature Nanotechnology, offers a
new tool for tracking specific chemicals in the body.
"We made a very small nanosensor that can detect cancer-causing molecules
or important therapeutic drugs inside of a single living cell," said Michael
Strano of Massachusetts Institute of Technology in Cambridge, who worked on
the study.
"It's much smaller than a living cell in your body. It's so small that
it can be placed into environments that aren't accessible with larger sensors,"
said Strano. He further said that the sensors are made up of thin filaments
of carbon molecules known as carbon nanotubes.
Several teams are using nanomaterials which are thousands of times smaller than
the width of a human hair to develop new ways to deliver drugs in the body or
improve diagnosis of disease. For its sensors, Strano's team wrapped carefully
shaped carbon nanotubes with DNA, which offers a binding site for DNA-damaging
agents inside cells.
The sensors give off a fluorescent light that can be detected in the near-infrared
light spectrum. Because human tissues do not light up in this spectrum, the
nanotubes stand out. Strano said the light signal changes when the sensors interact
with DNA inside cells. These changes can help them identify specific molecules.
"It's a way of fingerprinting chemistry," Strano said. Because the
sensors are coated in DNA, they can be safely injected into living cells. "Eventually
the cell eats the protein off the coating and it essentially spits it out,"
he said.
He said the most immediate use of the technology will be as a very powerful
tool for scientists to study the effects of very small amounts of a chemical.
But it could eventually be used as a new way to image the human body. "It's
a new tool. There is nothing else like it," said Strano.
Reuters
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