Image: The iEAT system for onsite antigen detection consists of a pocket-sized detector, an electrode chip, and a disposable kit for allergen extraction. The detector connects with a smartphone for system control and data upload to a cloud server (Photo courtesy of Lin, et al. ACS Nano, August 2017).
Researchers have developed a small, low cost device for individual use that can accurately detect food allergens in less than ten minutes.
Adverse food reactions, including food allergies, food sensitivities, and autoimmune reaction (e.g., celiac disease) affect 5-15% of the population of the USA and remain a considerable public health problem requiring stringent food avoidance and epinephrine availability for emergency events. Avoiding problematic foods is difficult in practical terms, given current reliance on prepared foods and out-of-home meals.
In response to the food allergy problem, investigators at Harvard Medical School (Boston, MA, USA) developed a portable, point-of-use detection technology, that they called "integrated exogenous antigen testing" (iEAT).
The iEAT device consists of three components: (1) a small plastic test tube, (2) a small electronic detection module, and (3) the electronic keychain reader. To perform the test, the user dissolves a small sample of the food in the plastic test tube and then adds magnetic beads that capture the food allergen of interest. A bit of this mixture is loaded onto electrode strips attached to a small module that is then inserted into the electronic keychain reader. The keychain reader has a small display that indicates whether the allergen is present, and if so, in what concentration.
The prototype iEAT system was optimized to detect five major food antigens in peanuts, hazelnuts, wheat, milk, and eggs. Antigen extraction and detection with iEAT required less than 10 minutes and achieved high-detection sensitivities (e.g., 0.1 milligram per kilogram for gluten, 200 times lower than regulatory limits of 20 milligram per kilogram).
The investigators also developed a dedicated cell phone application, which allows the user to compile and store the data collected by testing different foods for various allergens at different restaurants or in packaged foods. The application is set up to share this information online with both time and location stamps indicating when, where, and in what food or dish an allergen reading was taken.
“High accuracy built into a compact system was the key goals of the project,” said contributing author Dr. Ralph Weissleder, professor of radiology and systems biology at Harvard Medical School. “Users can be confident that even if they are sensitive to very low levels, iEAT will be able to give them exact concentrations. Armed with accurate concentration levels they will not have to completely avoid potentially problematic foods, but will know whether an allergen is at a dangerous level for them or a concentration that is safe for them to eat.”
The iEAT device was described in the August 2017 issue of the journal ACS Nano.
Harvard Medical School