A new peripheral for smartphones recently announced by researchers at UCLA heralded what is quite simply one of the most disruptive digital health innovations I have yet encountered. A team at the Ozcan Lab has developed a smartphone peripheral, manufactured using a 3D printer, which can use the phone’s camera to determine the amount of a specific allergen in any given food item.
Food allergies affect approximately 8 percent of children and 2 percent of adults, with allergic reactions ranging from a little itching to life-threatening airway swelling. The food consumer protection act required that all processed foods be properly labeled, ensuring individuals will have all the information necessary to make intelligent decisions when selecting which foods to eat. However, there is still the possibility of unlabeled allergens being present in food due to cross-contamination during processing or preparation.
Several technologies have been developed to aid in the detection of specific allergens, including those based on polymerase chain reaction (PCR), mass spectroscopy, antibody-based immunoassays, surface-plasmon-resonance (SPR) biosensors, array immunoassays, electrochemical immunosensors – the list goes on and on. While these approaches have achieved high levels of sensitivity, they are also quite complex and involve the use of heavy equipment, making them impractical for personal use.
To address this problem, the Ozcan Lab team developed a personalized allergen testing device they call iTube that utilizes a sensitive colorimetric assay to detect the substance of interest, say peanuts, in the food being tested. As described in the press release,
To test for allergens, food samples are initially ground up and mixed in a test tube with hot water and an extraction solvent; this mixture is allowed to set for several minutes. Then, following a step-by-step procedure, the prepared sample is mixed with a series of other reactive testing liquids. The entire preparation takes roughly 20 minutes. When the sample is ready, it is measured optically for allergen concentration through the iTube platform, using the cell phone’s camera and a smart application running on the phone.
After processing, the user uses the associated Android application to analyze the sample using the smartphone peripheral and the smartphones camera.
And beyond just a “yes” or “no” answer as to whether allergens are present, the test can also quantify how much of an allergen is in a sample, in parts per million.
To test the device, researchers traveled to their local Mrs. Fields Cookies to purchase three different types of cookies – peanut butter chocolate, milk chocolate chip, and oatmeal raisin with walnut. These cookies were each tested three separate times for quantification of their peanut content. The peanut butter cookies, as expected, tested positive for peanut content, though for purposes of the experiment the peanut contents were drastically diluted by the research team. Also as expected, both the milk chocolate chip and oatmeal raisin with walnut cookies tested negative for peanut content.
While the team only tested the iTube for its ability to detect peanut content, the platform can also be used to detect a variety of other common allergens including almonds, eggs, gluten, hazelnut, lupine, mustard, sesame, crustacean, soy, and even milk. There is almost certainly a commercial application for this product, so it will be interesting to see what becomes of the iTube platform in the coming months.
Details of how iTube works were laid out in a paper published by the group in the journal Lab on a Chip.