This 18-Year-Old Developed a Test to Find Out If Your Drink Has Been Spiked

The simple and inexpensive sensor detects the antihistamine in “Benadryl cocktails”

Angie Fogarty in the lab
Angie Fogarty tested at least 100 different versions of her sensor before finding the perfect formula. Angie Fogarty

It was the day after Christmas 2021, and Angie Fogarty sat in a dark room with an ultraviolet flashlight trained on a tiny, hole-punch-sized circle of paper in front of her. She carefully placed a few drops of liquid on the red paper, then cast a UV spotlight on the spot as she waited in anticipation. Almost instantly, it turned green.

“I started crying, it was so exciting,” says the now 18-year-old senior at Greenwich High School in Greenwich, Connecticut.

She had finally had a breakthrough in her research project, creating a sensor that detects the presence of diphenhydramine (DPH), the ingredient in Benadryl that causes drowsiness, in drinks. Meant to prevent drugging and drug-facilitated sexual assaults, the sensor is small, inexpensive and easy to use.

This innovation is what made Fogarty one of 40 finalists in the 2023 Regeneron Science Talent Search, the country’s oldest and most prestigious science and math competition for high school seniors. The competition’s top prizes this year went to a student who designed a computer model that can predict the structure of RNA molecules, with the goal of making it easier to diagnose and treat certain diseases, and another who used artificial intelligence to show that the Boston Globe’s descriptions of homicide victims from 1976 to 1984 were less humanizing in coverage of Black victims.

Entrants in the Science Talent Search often choose to focus on issues that directly affect them or their community, says Maya Ajmera, the president and CEO of Society for Science, which runs the competition. This year’s third-place finisher, Ellen Xu, developed an algorithm that aids in the diagnosis of Kawasaki disease, the leading cause of acquired heart disease in children between 1 and 5 years old, which her younger sister was diagnosed with.

“A lot of these projects are so fascinating because they look at an issue that’s close to home for them,” Ajmera says.

Angie Fogarty presents at the 2023 Regeneron Science Talent Search
Fogarty was one of 40 finalists in the 2023 Regeneron Science Talent Search, the country’s oldest and most prestigious science and math competition for high school seniors. Angie Fogarty

From the beginning, Fogarty knew she wanted to focus her project on women’s health. As she embarked on her college search, the teenager kept seeing headlines about drink spiking and drug-facilitated sexual assaults on various campuses, dampening her excitement to attend.

“It was so discouraging,” she says. “Unfortunately, a lot of young women and young people in general aren’t guaranteed this degree of safety that should be a basic right.”

Fogarty was thinking specifically of preventing drugging on college campuses as she designed her project, though the sensor can be used by anyone seeking to test their drink. A 2017 study of more than 6,000 college students at three universities in Psychology of Violence found that more than 1 in 13 believed they had been drugged, though the researchers caution that they cannot confirm respondents were drugged, and some respondents were unsure. Over twice as many women as men reported being drugged, and women tended to mention sex or sexual assault as a motive, while men tended to mention having fun.

In the hopes of creating a safer environment for everyone, Fogarty landed on her project idea: a simple, color-changing sensor that can tell someone whether an antihistamine has been slipped into their drink. If an individual is wary of a drink, they can place a small amount of the beverage in a bottle, add a few drops of a provided pH adjuster until the liquid becomes a pale yellow, then put a dab of the solution on the sensor, which turns red or green depending on whether the liquid contains DPH or not.

Of course, creating something simple is exactly what made the research process so complex. Fogarty calls the months from November 2021 to March 2022 “the dark ages.”

“I had no free time,” she says. “There was not a weekend, there was not a school break, not an evening that I wasn’t [working].”

First, Fogarty had to figure out how to get the right reaction when DPH hit the sensor. After reviewing other research literature and testing methods, she settled on a two-dye system. She put two dyes, one green, one purple, on a small piece of cellulose paper—a material commonly used for test strips.

When a liquid without DPH meets the paper, the green dye dissolves in the liquid, pulling it up and away from the paper so it glows when hit by ultraviolet light. Meanwhile, the purple dye, bonded with the paper, remains hidden underneath.

On the other hand, when the paper meets DPH-containing liquid, a chemical linkage forms between the green dye and the drug, dampening the expression of the dye and allowing the color of the purple dye to show through. Under UV light, the sensor is a red color.

Working with the two dyes made for a challenging task. “Whenever I would make an alteration to one of the dyes, it could negatively impact the other,” Fogarty says. “That’s why I was stuck for so long in the trial-and-error phase.”

Mastering the color-changing effect is what gave Fogarty her Christmas eureka moment. However, that was only the first step—there was much more testing yet to do.

“Because the sensor is supposed to be used to prevent date rape, that involves a lot of alcoholic beverages, which means there could be additives, there could be colors,” Fogarty says. “There were a ton of other variables which were pretty difficult to navigate, especially because I’d spent so long just trying to get the sensor to work with just reacting to the drug. Then it was, ‘Oh, you did that, now does it work in orange juice?’”

As she tested her sensor in mixed drinks, Fogarty found that the acidity of different beverages changed the reaction between the dyes that forms the basis of the test. Eventually, she discovered that adding a tiny amount of sodium hydroxide could standardize the acidity of the beverage, allowing the process to work as planned.

Overall, she estimates that she tested “at least a hundred, probably more” different versions of the sensor before finding the perfect formula. Since it requires tiny amounts of dye, each test only runs around $1 to produce.

Fogarty wanted her sensor to be not only economically accessible but also easy to use. Other drink-spiking detection tests developed for drugs like the sedatives gamma-hydroxybutyrate (GHB) and Rohypnol (few existing tests, if any, detect DPH) often use a lateral-flow test technique, an approach that is common in Covid-19 self-testing. However, these can come with complicated directions, and the movement of liquid and mixing of test agents can be easy to accidentally disturb.

“If you’re testing it in a dark room, which is most likely where you’d find yourself in these kinds of scenarios, it’s hard to be able to distinguish whether or not you have this faint line,” Fogarty says. “That’s why I wanted to do the color system.”

Even with improved usability, another barrier to drink-spiking tests is getting people to actually use them, says Pamela Donovan, a sociologist and author of Drink Spiking and Predatory Drugging: A Modern History. “A lot of people support the idea of getting them and using them, but if you look at all these companies that sell them or you try to follow up with places that have handed them out, basically, there’s no further news, there’s very little in the way of testimonials.”

“I’m not sure why this is, but most people just won’t use them,” she adds.

Additionally, many tests currently on the market can be unreliable. Some tests meant to detect GHB will give a false positive when exposed to liquids like Evian water, dairy or red wine, Donovan says.

While there’s still much to be studied when it comes to the uptake of tests, Donovan sees potential in Fogarty’s project. Existing tests, she says, offer the ability to test for drugs like GHB or ketamine, another drug used in social settings that can also be a drugging agent. “I wonder whether adding a DPH spot [to these tests] would make it seem more comprehensive to potential marketplace consumers,” she says.

Donovan also speculates that the test could be usefully adapted to detect DPH in other situations. The Centers for Disease Control and Prevention has reported early evidence that DPH may be a contributing factor to opioid overdose, and it may sometimes be mixed into the drug supply. Additionally, DPH may interfere with the use of nasal rescue spray in the case of overdoses. If the test could be adapted to detect adulterants, it could both help drug users avoid overdose and give experts more knowledge about the drug supply.

Fogarty herself has also noted another potential use for her test. Because of the way the sensor works, it can be adapted to detect pyrrole, a compound found in marijuana. The adapted sensor, when wetted, can be used as a breathalyzer to determine if someone is under the influence of cannabis and therefore unable to safely drive.

With the $25,000 in prize money awarded to her as a competition finalist, Fogarty plans to pursue patents and marketing for the sensor and its potential extended use. Some of the funds will also be set aside to pay for her tuition at Washington University in St. Louis, where she will study biology with the goal of becoming a veterinarian.

Fogarty’s also eager to see what the other young scientists in the Science Talent Search continue to do now that their work has been recognized.

“It’s great to see so many of these young adults being highlighted for the work they’re doing, and being validated, getting tons of new opportunities, because it’s all so well deserved," she says. "It’s bringing attention to a lot of important issues."

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