UCLA smartphone attachment detects food allergens
By David Szondy
December 16, 2012
If you’re the parent of a child with food allergies, you know how terrifying they can be. Such allergies can be life threatening and, despite food labeling laws, it isn't always possible to be certain some potentially deadly ingredient isn't lurking in an item. In an effort to improve on the bulky and complex allergen detectors currently available, researchers from the UCLA Henry Samueli School of Engineering and Applied Science have developed a device called the iTube that turns a smartphone into an allergen sensor.
Developed by a team led by Aydogan Ozcan, associate professor of electrical engineering and bioengineering at UCLA , the iTube attaches to a smartphone and detects food allergens with laboratory-level sensitivity. The device weighs about 40 grams (1.41 oz) and can detect a number of allergens, including peanuts, almonds, eggs, gluten and hazelnuts.
It is not, however, very simple to use and the test takes some time. Though the iTube can measure a sample’s allergen concentration in a second, preparing the test sample takes 20 minutes and several steps, so you won’t be using this to check your daughter’s chicken nuggets at the drive through.
The iTube detects allergens by means of colorimetric assay. That is, it works by chemically coloring the allergens in a solution and then measuring them by the concentration of the color. To analyze food, a sample is ground up by the user and mixed with hot water and an extraction solvent in a test tube. After this is allowed to settle for a several minutes the sample is mixed with a series of chemical reagents. The prepared sample and a control tube are then placed in the device, lit by LEDs and measured optically using the phone’s camera and an app that compares the sample and control to measure allergen concentrations. The test tells whether allergens are present and quantifies this in parts per million.
The test results are location and time stamped and the app uploads the data to iTube servers to create a personalized allergy database for statistical analysis.
"We envision that this cell phone–based allergen testing platform could be very valuable, especially for parents, as well as for schools, restaurants and other public settings," Ozcan said. "Once successfully deployed in these settings, the big amount of data – as a function of both location and time – that this platform will continuously generate would indeed be priceless for consumers, food manufacturers, policymakers and researchers, among others."
The iTube has been tested on samples of commercially-available cookies to determine if peanuts were present. The results are published online in the Lab on a Chip journal.