Joyce Tian, left, and Pallavi Bhave won a national science contest this spring with their idea for the Food Allergen Detector, a device with lasers that would tell people if a potential allergen, such as nuts or milk, was present in their food. (Moira E. McLaughlin/The Washington Post)

Chances are good that you know someone who is allergic to some type of food — maybe peanuts, milk or eggs. Researchers at an organization called the Centers for Disease Control and Prevention think that one kid in every 20 has a food allergy.

Two Vienna middle-schoolers came up with an idea that may help them.

It’s called the Food Allergen Detector, or FAD. (Allergen is the thing — peanuts, for instance — that causes an allergic reaction.)

“Since so many people have allergies, we thought that this would be a good idea,” said Pallavi Bhave, 14.

Detecting allergens

Pallavi and classmate Joyce Tian, 13, won a national science competition this spring for coming up with the concept for FAD. The two girls, who just graduated from Kilmer Middle School in Vienna, beat 675 teams of seventh-to-ninth-graders in their region, which was made up of six states and Washington, D.C.

While the girls didn’t make the FAD — the necessary technology doesn’t exist yet — they came up with the information that could lead to its invention. They wrote an 11-page paper for the judges, working after school and on weekends for about three weeks. Their goal was to make the FAD something that would be convenient, easy to use and inexpensive.

It works like this: Let’s say you’re allergic to peanuts and you go out to dinner. You order chocolate cake for dessert, but you’re worried that it might contain peanuts. Take out your FAD, which would be about the size of a cellphone, and point it at the cake. The FAD would shoot two laser beams, one green and one invisible, at the cake. A list of 50 allergens would appear on the FAD screen with the word “yes” or “no” beside them.

Each of the 50 food items would have a unique “fingerprint,” the girls said. The FAD would use a technology called Raman spectroscopy to identify the allergens in your chocolate cake.

If “no” appears beside the word “peanut,” you’re safe to eat the cake!

In the future

Joyce and Pallavi plan on being scientists when they grow up. Pallavi wants to be a genetic engineer; that is someone who works with DNA (which is the backbone of all life). Joyce, whose dad is a chemist (someone who studies what things are made of), has been studying the periodic table since she was a toddler. (The periodic table is what scientists use to organize chemical elements, including hydrogen and helium.)

The girls intend to keep working on the FAD in ninth grade at Thomas Jefferson High School for Science and Technology in Fairfax County this fall. If all goes well, worrying that peanuts might be in your chocolate cake could be a thing of the past.

Moira E. McLaughlin