Food allergies are extremely common. In the US, Federal regulations require packaged foods to disclose the presence of some of the most common allergens such as gluten, nuts, and milk products, which is helpful, but not always accurate.

The iEAT system for onsite antigen detection consists of a pocket-size detector, an electrode chip, and a disposable kit for allergen extraction. (Image courtesy of Lin, et al. ACS Nano, Aug-2017)

Researchers at Harvard Medical School in Boston have developed a system called integrated exogenous antigen testing (iEAT), whose purpose is to give those who suffer from food allergies a rapid, accurate device that allows them to personally test foods in less than 10 minutes.

The researchers have taken technologies they developed for other medical problems, such as early cancer detection from blood samples, and applied them to solving the daily, potentially life-threatening difficulties, of people with food allergies — a highly significant public health problem that incurs 25 billion dollars in annual costs in the U.S. alone.

The device consists of three components. A small plastic test tube is used to dissolve a sample of the food being tested and to add it to the magnetic beads that capture the food allergen of interest, such as gluten. A bit of that solution is dropped onto electrode strips in a small module that is then inserted into the electronic keychain reader. The reader has a display that indicates whether the allergen is present, and if so, in what concentration.

Testing showed that measurements of the concentration of the allergen are extremely accurate, which is very important. For example, even though Federal standards say that a food is considered gluten free if it has a concentration of less than 20 mg per kg of gluten, everyone's sensitivity is different, and many people would have a reaction at much lower gluten concentrations. Extensive testing of iEAT revealed that the system could detect levels of gluten that were 200 times lower than the Federal standard.

Beyond obtaining the information they need in about 10 minutes using iEAT, a novel addition to the system is the development of a cell phone app, which offers the possibility of addressing food allergies at the community level. Using the app, users can compile and store the data they collect as they test different foods for various allergens at different restaurants and even in packaged foods. The app 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. With the app, people will eventually have a personal record of levels that trigger a reaction. Others with the app will be able to find restaurants with foods they like to eat, that consistently have no or low levels that are below the individual's triggering concentration.

In addition to contributing to food safety at the individual and community levels in the U.S., the inventors point out that the device would be very valuable for travelers in countries where there are no specific requirements for food labels.

Another use of the system would be to trace the source of food contamination with bacteria such as E. Coli or Salmonella to a specific food-processing site by testing DNA in the samples to potentially identify and contain an outbreak more quickly.

For more information, contact Thomas Johnson at 301-496-3500, This email address is being protected from spambots. You need JavaScript enabled to view it.


Sensor Technology Magazine

This article first appeared in the March, 2018 issue of Sensor Technology Magazine.

Read more articles from this issue here.

Read more articles from the archives here.