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A Biodetection Lab In Your Hand
Smartphone As Biosensor Detects Molecules/Toxins
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Cradle turns smartphone into handheld biosensor
Researchers and physicians in the field could soon run on-
the-spot tests for environmental toxins, medical diagnos-
tics, food safety and more with their smartphones.
University of Illinois at Urbana-Champaign researchers
have developed a cradle and app for the iPhone that uses
the phone¡¯s built-in camera and processing power as a bio-
sensor to detect toxins, proteins, bacteria, viruses and other
molecules.
Having such sensitive biosensing capabilities in the field
could enable on-the-spot tracking of groundwater contami-
nation, combine the phone¡¯s GPS data with biosensing
2013 June #4-5
working to improve the manufacturing process for the iPhone cradle and
are working on a cradle for Android phones as well. They hope to begin
making the cradles available next year.
Cunningham¡¯s group is now collaborating with other groups across campus
at the U. of I. to explore applications for the iPhone biosensor. The group
recently received a grant from the National Science Foundation to expand
the range of biological experiments that can be performed with the phone,
in collaboration with Steven Lumetta, a professor of electrical and computer
engineering and of computer science at Illinois. They are also working with
food science and human nutrition professor Juan Andrade to develop a
fast biosensor test for iron deficiency and vitamin A deficiency in expectant
mothers and children. Cunningham¡¯s team is also working on biosensing
tests that could be performed in the field to detect toxins in harvested corn
and soybeans, and to detect pathogens in food and water.
¡°It¡¯s our goal to expand the range of biological experiments that can be
performed with a phone and its camera being used as a spectrometer,¡± Cun-
ningham said. ¡°In our first paper, we showed the ability to use a photonic
crystal biosensor, but in our NSF grant, we¡¯re creating a multi-mode biosen-
sor. We¡¯ll use the phone and one cradle to perform four of the most widely
used biosensing assays that are available.¡±
Cunningham also is affiliated with the Institute for Genomic Biology, the
Beckman Institute for Advanced Science and Technology, and the Micro and
Nanotechnology Laboratory at Illinois.
The paper, ¡°Label-free biodetection using a smartphone,¡± is available at:
pubs.rsc.org/en/content/articlelanding/2013/lc/c3lc40991k
(Source: by EAI - May 23, engineeringatil.scienceblog.com)
data to map the spread of pathogens, or provide immediate and inexpensive
medical diagnostic tests in field clinics or contaminant checks in the food pro-
cessing and distribution chain.
¡°We¡¯re interested in biodetection that needs to be performed outside of the labo-
ratory,¡± said team leader Brian Cunningham, a professor of electrical and com-
puter engineering and of bioengineering at Illinois. ¡°Smartphones are making a
big impact on our society ¨C the way we get our information, the way we com-
municate. And they have really powerful computing capability and imaging. A
lot of medical conditions might be monitored very inexpensively and non-in-
vasively using mobile platforms like phones. They can detect molecular things,
like pathogens, disease biomarkers or DNA, things that are currently only done
in big diagnostic labs with lots of expense and large volumes of blood.¡±
The wedge-shaped cradle contains a series of optical components, lenses and
filters, found in much larger and more expensive laboratory devices. The cradle
holds the phone¡¯s camera in alignment with the optical components.
At the heart of the biosensor is a photonic crystal. A photonic crystal is like a
mirror that only reflects one wavelength of light while the rest of the spectrum
passes through. When anything biological attaches to the photonic crystal, such
as protein, cells, pathogens or DNA, the reflected color will shift from a shorter
wavelength to a longer wavelength.
For the handheld iPhone biosensor, a normal microscope slide is coated with
the photonic material. The slide is primed to react to a specific target molecule.
The photonic crystal slide is inserted into a slot on the cradle and the spectrum
measured. Its reflecting wavelength shows up as a black gap in the spectrum.
After exposure to the test sample, the spectrum is re-measured. The degree of
shift in the reflected wavelength tells the app how much of the target molecule
is in the sample.
The entire test takes only a few minutes; the app walks
the user through the process step by step. Although the
cradle holds only about $200 of optical components,
it performs as accurately as a large $50,000 spectro-
photometer in the laboratory. So now, the device is
not only portable, but also affordable for fieldwork in
developing nations.
In a paper published in the journal Lab on a Chip,
the team demonstrated sensing of an immune system
protein, but the slide could be primed for any type of
biological molecule or cell type. The researchers are
Medical diagnostics & food safety go mobile