Cradle Turns Smartphone Into Handheld Biosensor

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 biosensor to detect toxins, proteins, bacteria, viruses and other molecules.

Researchers and physicians in the field could soon run on-the-spot tests for environmental toxins, medical diagnostics, food safety and more with their smartphones. Having such sensitive biosensing capabilities in the field could enable on-the-spot tracking of groundwater contamination, combine the phone's GPS data with biosensing data to map the spread of pathogens, or provide immediate and inexpensive medical diagnostic tests in field clinics or contaminant checks in the food processing and distribution chain.

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.

"We're interested in biodetection that needs to be performed outside of the laboratory," said team leader Brian Cunningham.Smartphones are making a big impact on our society -- the way we get our information, the way we communicate. And they have really powerful computing capability and imaging. A lot of medical conditions might be monitored very inexpensively and non-invasively 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."