Study: $40 keychain could accurately detect food allergens

By Dave Muoio

Researchers at Harvard Medical School have built a point-of-use food allergen detector that fits onto a keychain and can conducts tests in under ten minutes.

The prototype device costs less than $40 to produce, and in restaurant settings could detect major antigens at sensitivities well below the regulatory limit. While the sensitivity and ease of the integrated exogenous antigen testing (iEAT) system could be of use to clinicians and food industry regulators, the researchers noted its particular appeal to on-the-go consumers often forced to carry emergency epinephrine and maintain strict food avoidance.

“Many existing analytical methods and devices for food testing are designed for sophisticated laboratory rather than consumer use and rely on complex equipment, infrastructure, and advanced training,” they wrote in the journal ACS Nano. “Consumer devices, on the other hand, are often slow, insensitive, or have other limitations … Moreover, their relatively low sensitivity, caused by insufficient brightness of signal-intensity reporters, may result in false negative results.”

The full system consists of an electrode chip, a disposable allergen extraction kit, and a pocket-sized detector that interfaces with a smartphone and can connect to cloud servers. Each assay costs less than four dollars, although the researchers wrote that costs for the entire system could decrease with scale-up.

In the study, researchers optimized the iEAT system to detect five major antigens found in peanuts, hazelnuts, wheat, milk, and eggs. After observing strong correlation between the iEAT system’s results and those of industry-standard enzyme-linked immunosorbent assay (ELISA), the researchers tested the novel system’s sensitivity using various consumer food products and foods purchased from restaurants.

iEAT detected allergens at sensitivities substantially lower than the standard regulatory limit, and in particular identified multiple cases in which the antigen levels of menu items labeled as “gluten-free” exceeded the 20 mg/kg regulatory limit.

“The device could have many interesting applications, such as verifying food origins, confirming the absence of contaminants, or supporting dietary restrictions for religious purposes,” the researchers wrote. “Irrespective of the specific application, we envision that the portable iEAT technology will allow for more rigorous and evidence-based analysis of food products, enhance consumer protection, reduce accidental allergy exposure, and identify problems in our food supply chain.”

iEAT offers a low-cost alternative to the Nima brand’s smartphone-connected allergen detectors. Currently, the company sells a starter kit that includes the device and three one-time-use test capsules for $199.