The Becoming Gentleman™

This High Schooler Invented Color-Changing Sutures to Detect Infection

By Theresa Machemer

Dasia Taylor has juiced about three dozen beets in the last 18 months. The root vegetables, she’s found, provide the perfect dye for her invention: suture thread that changes color, from bright red to dark purple, when a surgical wound becomes infected.

The 17-year-old student at Iowa City West High School in Iowa City, Iowa, began working on the project in October 2019, after her chemistry teacher shared information about state-wide science fairs with the class. As she developed her sutures, she nabbed awards at several regional science fairs, before advancing to the national stage. This January, Taylor was named one of 40 finalists in the Regeneron Science Talent Search, the country’s oldest and most prestigious science and math competition for high school seniors.

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“I’ve done a lot of racial equity work in my community, I’ve been a guest speaker at several conferences,” says Taylor. “So when I was presented with this opportunity to do research, I couldn’t help but go at it with an equity lens.”

Before the Covid-19 pandemic, Taylor spent most of her time after school in the Black History Game Show, a club she’s been a member of since eighth grade, and attending weekly school board and district meetings to advocate for an anti-racist curriculum. For the four months leading up to her first regional science fair in February 2020, Taylor committed Friday afternoons to research under the guidance of her chemistry teacher, Carolyn Walling.

Healthy human skin is naturally acidic, with a pH around five. But when a wound becomes infected, its pH goes up to about nine. Changes in pH can be detected without electronics; many fruits and vegetables are natural indicators that change color at different pH levels.

“I found that beets changed color at the perfect pH point,” says Taylor. Bright red beet juice turns dark purple at a pH of nine. “That’s perfect for an infected wound. And so, I was like, ‘Oh, okay. So beets is where it’s at.’”

Next, Taylor had to find a suture thread that would hold onto the dye. She tested ten different materials, including standard suture thread, for how well they picked up and held the dye, whether the dye changed color when its pH changed, and how their thickness compared to standard suture thread. After her school transitioned to remote learning, she could spend four or five hours in the lab on an asynchronous lesson day, running experiments.

A cotton-polyester blend checked all the boxes. After five minutes under an infection-like pH, the cotton-polyester thread changes from bright red to dark purple. After three days, the purple fades to light gray.

Working with an eye on equity in global health, she hopes that the color-changing sutures will someday help patients detect surgical site infections as early as possible so that they can seek medical care when it has the most impact. Taylor plans to patent her invention. In the meantime, she’s waiting for her final college admissions results.