A new biosensing tool puts the power of a high tech laboratory in the pockets of researchers in the field. This iPhone-enabled device could be used in pop-up clinics, waste management sites, refugee camps and anywhere else the mobile testing of biological materials such as blood is necessary.
Developed by researchers at the University of Illinois Urbana-Champaign, the tool consists of an iPhone cradle and an accompanying app. Although the cradle only holds about $200 worth of optical components, it performs as accurately as a $50,000 spectrophotometer.
The wedge-shaped cradle keeps the iPhone's camera aligned with a series of lenses and filaments, which are used to measure light. And at the heart of the device's biosensing capabilities is a simple microscope slide coated with a photonic material, which reflects only one wavelength of light and allows the rest of the spectrum to pass through the slide.
When a biological substance — like protein or DNA — attaches itself to the photonic crystal slide, the color that is reflected will shift from a shorter to longer wavelength. The size of this shift depends on the amount of the substance present on the slide.
So to test for the presence of a protein, for example, researchers would first prime the slide with the protein they want to test for, insert the slide into the cradle and then use the app to measure the length of the protein's reflected wavelength. This gives them a base measurement.
They can then expose the slide to a field sample containing the protein and remeasure the wavelength. The shift in the
reflected wavelength tells the researchers how much of the protein is present in the sample.
The test takes only a few minutes to complete, and the app walks the user through the entire process. This means that samples that once had to be sent back to a lab for analysis can now be tested on-the-spot in a matter of minutes.
Researchers have high hopes for this device as a viable option for doctors, nurses, scientists and others in need of efficient, affordable biological testing on the go. They think it could be particularly useful in developing countries, where resources are limited and laboratories are scarce.
With help from the iPhone's GPS tool, the device could even be used to track
groundwater contamination, map the spread of pathogens or monitor contaminant checks in the food processing and distribution chain, according to researchers.
"We're interested in biodetection that needs to be performed outside of the laboratory," said Brian Cunningham, professor of electrical and computer engineering at the University of Illinois. "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."
The team is now working on a similar cradle and app solution to provide mobile testing on Android devices.
And a recent grant from the National Science Foundation is enabling researchers to expand the range of biological experiments that can be performed with the tool, including tests that will detect toxins in harvested corn and soybeans, as well as tests to detect pathogens in food and water.
The use of smartphones as a platform for detecting environmental phenomena seems to be a growing trend, not only among researchers, but consumers as well.
In the past year, a number of
smartphone-enabled tools and accompanying apps have come on the market that measure everything from the "organic-ness" of fruits to the temperature of soil in a vegetable garden.
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