030
Not Without a Trace
Devices in the works would track even microbial DNA
for better health, security
WRI TING BY :: SCIENCE FOUNDATION ARIZONA AND WAYNE FRASCH
attract outside investment to manufacture the
DNA-detection device. This has enabled the
ASU team to extend the technology platform to
perform protein detection at the single molecule
level, an important step in understanding human
health and disease.
Avidin
Gold nanorod
DNA
Biotin
growing health-care concern
in recent years has been the
emergence of microbes that
increasingly are resistant to
the traditional first line of
defense: antibiotics.
As a society, we also face the risk of newly
evolved infectious diseases, such as SARS, avian
flu and swine flu, and threats to national security
from bioterrorism. In today’s global economy
and transportation sector, these threats can
rapidly spread across borders and continents.
To mitigate the threat from infectious
pathogens, scientists at Arizona State University
are using the ultimate biological detective,
DNA, to develop new devices that can rapidly
detect the microbial threats to human health
and national security. With an investment grant
from Science Foundation Arizona, lead scientist
Wayne Frasch and his co-workers at ASU have
established the groundwork for nanotechnology-based biosensors that can sniff out even trace
amounts of microbial DNA.
One such biosenser is a small, portable “lab
on a chip.” It could thwart bioterrorism threats
like anthrax, revolutionize health screenings
for diseases caused by antibiotic-resistant staph
found in hospitals, and even be applied to
identify DNA defects linked to cancer.
a
A tissue-box-sized prototype of a DNA
detector is currently in development using the
biosenser device. It uses nanotechnology based
on the world’s tiniest rotary motor: a biological,
spinning-top-shaped engine called F1-ATPase.
This molecule is one of nature’s nanosized
molecular motors, acting like a rotary engine
to generate torque and make ATP (adenosine
triphosphate) the energy currency of every cell.
The tiny, spinning F1-ATPase motor can detect
minute amounts of DNA, even down to the level
of single DNA molecules, far exceeding detection
limits of conventional DNA technology. Such a
detection instrument also would be faster, cheaper
and more portable than existing technology.
The ASU team envisions that the device
would be routinely used in health-care clinics
and to screen luggage passing through airport
security checkpoints, leading to substantial
commercialization potential. Sampling would be as
simple as taking a swab from an infected wound or
a piece of baggage, dissolving it in a solution and
placing a drop on a slide containing the nanoparts
to do the DNA detective work. Red blinking
signals emitted by rotating nanorods would let a
computer know there’s trouble, literally, in a flash.
With support from Science Foundation
Arizona, the team is transferring the work from
the bench to biotech development by helping
+ Target DNA forms
part of a molecular
tether between a
tiny nano-motor
(named F1-ATPase) and
microscopic gold
material, the gold
nanorod. When a single
molecule of a specific target
DNA is added, the whirling, nano-sized
complex emits a pulsing red signal that
can be detected.
g
F1-ATPase
