Nicole Auvil Awarded Kwolek Fellowship

Nicole Auvil first became interested in chemistry and machines as a high school student working for Lusso Cosmetics in her hometown of Lakewood, Ohio.

"Working at Lusso I was able to see the full cosmetic production process from receiving raw material shipments to selling product to customers. It was a pretty cool after-school job," Auvil said. Because the company was small, she helped do everything from stocking shelves and selecting makeup for customers to making batches of product from scratch. "I developed an affinity for working in the lab. Once I got production batches down, I was able to start research and development."

While she formulated shimmery eyeshadow, liquid lipsticks and a face cream, she wanted to learn more about what was happening on the molecular level. So, when college came, she majored in chemistry at The Ohio State University. Her time in the lab studying sea spray, testing chemicals in drinking water and building devices led her to sharpen her focus to analytical instrumentation. She applied to Carnegie Mellon's doctoral program and joined the Bier's Group.

"If you work in instrument development, you can create tools that may be useful for a wide variety of disciplines and applications. Which is what led me to be interested in the Bier Group," she said.

Auvil is a graduate student in the research group led by Mark Bier, research professor in chemistry and director for the Center for Molecular Analysis at Carnegie Mellon. As an expert in the field of mass spectrometry, he and his students like Auvil work to build improved instrumentation and methods to make improved mass-to-charge (m/z) measurements of different molecules. Mass spectrometers are a class of instruments used by scientists to characterize molecules.

Among the more than a dozen patents related to mass spectrometry Bier and his lab have worked on is one for a “super-sniffer” that Bier and Auvil share.

In Auvil's first semester, Bier offered up several building projects including one that had been unsuccessfully attempted by previous students. The challenge: figuring out how to reproducibly make ultrasharp needles out of tungsten metal and develop a mass spectrometer ionization source with which to use them.

"That was a tricky task," she said. "At the time, we didn't know if it would be possible to make needles this sharp with such an intense geometry... and to make them reproducibly? I knew I was taking on a project that might not be successful."

The needle's job is to emit a highly energetic plasma called a corona discharge. The sharper the needle, the lower the voltage it requires to do this job. Corona discharge ionizes the ambient air (and whatever molecules it may contain) in a small region around the needle tip — a proton is added, or one or more electrons are knocked off to create positive ions.

"We are wondering whether two ionization mechanisms are at play here," Bier said.

The ions are then sucked into a vacuum chamber and into a mass analyzer for mass-to-charge analysis and detection. For a linear ion trap mass analyzer — one of Bier's most impactful inventions — this is accomplished by measuring the point of radial ion ejection of each ion out of the trapping region. The instrument records the relative abundances of an ion’s mass-to-charge to produce a visual read-out called a mass spectrum.

Commercial needles used for atmospheric pressure chemical ionization typically have a tip radius greater than 14 microns at their sharpest point, thinner than a strand of human hair. Through an electrochemical etching process adapted from methods found in the literature, Auvil figured out how to make extremely sharp needles in-house that were as small as 8 nm, more than a thousand times smaller, by the start of her second semester.

"The first needles she showed me were fabulous with a beautiful parabolic tip," Bier said. "These needles turned out to be ultra-sharp, with a very desirable short tip, and they were reproducible, which was another goal of this aspect of the project. The needles were better than I had imagined and similar to the electron gun needles used in scanning electron microscopes."

Auvil said that mass spectrometry is one of the most important scientific instruments for humanity.

"People don't realize that so many items they use on a daily basis — medications, personal care products, food and beverages, even computer parts — have been tested by a mass spectrometer at some point or another," she said. "Mass spec is incredibly useful and broadly applicable for chemical testing, which is why I was drawn to it. Bier encourages us to innovate and think outside of the box. Once you hit a certain technical understanding, research is just as much art and creativity as it is science. I don’t want to lose sight of that."

Auvil approaches her work with a sharp attention to detail and through keeping an open mind. Her ability to explain her work in clear terms has helped her present in front of audiences such as medical professionals at the Pittsburgh International Lung Conference and judges at Carnegie Mellon’s 2024 Three-Minute Thesis competition, where doctoral students use one side and three minutes to explain complex research. She took third place.

For her efforts, Auvil was awarded the Kwolek Fellowship in Chemistry. The fellowship is awarded to women working toward their Ph.D. in chemistry who have demonstrated significant advances in their research.