Turning an iPhone into a biosensor

Researchers at the University of Illinois have created a cradle for an iPhone that turns it into a biosensor: this can detect pollutants, pathogens and toxins. The device could be used in fieldwork to detect pollutants in the environment, monitor disease or assess food safety.

The researchers created both an app and a cradle, which uses the iPhone’s camera as a biosensor to detect molecules. The cradle contains lenses and filters, and holds the phone’s camera in alignment with these optical components.  The main component of a biosensor is a photonic crystal, which is like a mirror that only reflects one wavelength of light.  When something biological attaches to the photonic crystal (like protein, cells or DNA), the reflected wavelength will become longer. For the iPhone biosensor, the photonic material is coated on a normal microscopic slide.  The slide is designed to react to a specific target molecule, and so can detect its presence in the environment the resulting shift in wavelength.

This cradle contains about $200 worth of optical components, but is as accurate as the large $50,000 spectrophotometers found in laboratories. As team leader Brian Cunningham says: “We’re interested in biodetection that needs to be performed outside of the laboratory.” Smartphones are great for this since they are portable and “have really powerful computing capability and imaging”.

The team have only shown how it can be used for one molecule, but the slide could be primed for a number of molecules.  For example, they are currently working to develop a way of testing for vitamin A deficiencies in children and pregnant women. As this technology develops it could be an important step in allowing researchers to collect accurate data in a non-invasive, quick and easy way.

See the device in action here: http://www.youtube.com/watch?v=Kh7MUjIYuyw