ACS Award For Creative Invention

David R. Walt’s career “exemplifies the very best in academia,” says Joseph M. DeSimone, a chemistry professor at the University of North Carolina, Chapel Hill. “He has pursued fundamental scientific inquiries that have resulted in the discovery of new phenomena. He has made careful measurements that have quantitatively grounded his discoveries. He has had the vision to see where these discoveries could address important unmet technological needs. And he has had the talents of execution and tenacity to drive the impacts of his discoveries into the marketplace.”

Walt, who is Robinson Professor of Chemistry and Howard Hughes Medical Institute Professor at Tufts University, has done these things while focusing on research in optical sensing arrays. He became interested in sensors through “serendipity,” he says. His work in immobilized enzymes, which he began as a postdoc with George M. Whitesides at Massachusetts Institute of Technology, netted Walt a consulting job with a company interested in medical sensors. “After I stopped consulting, I thought that using surface immobilization to develop sensors was a good area for exploration,” he says. “Almost no one knew what sensors were in those days, so it was a relatively open area with little competition.”

Walt, 56, “became interested in chemical sensors before this area was fashionable,” says Timothy M. Swager, professor of chemistry at MIT. “The era of chemical sensors, which now focuses as much on the materials as on the instrumentation, was ushered in partly by advances from Walt’s group.”

Walt pioneered using optical fibers for chemical sensing. One important advance involves selectively etching thousands of microwells at the ends of optical fibers used for imaging. Mixtures of microspheres labeled with different indicator chemistries can be assembled in random sensor arrays, with one microsphere in each well.

That technology became the foundation for the San Diego-based company Illumina, which is now a powerhouse in micro­array and next-generation DNA sequencing technologies. “Founding a successful company has been a tremendous thrill and a source of great satisfaction,” Walt says. He continues to serve on Illumina’s board of directors and as the head of its scientific advisory board.

Walt is also the founder of the Cambridge, Mass.-based company Quanterix, which focuses on protein diagnostics that employ etched microwell arrays. The technology can detect binding of many single protein molecules simultaneously.

Walt received a B.S. in chemistry from the University of Michigan in 1974. In 1979, he received a Ph.D. in chemical biology—a joint degree in chemistry and pharmacology—from the State University of New York, Stony Brook, where he worked with Francis Johnson. From 1979 to 1981, he was a postdoctoral research associate with Whitesides at MIT.

Since 1981, Walt has been a member of the chemistry faculty at Tufts. He was promoted to associate professor in 1986 and to full professor in 1992.

He was elected to the National Academy of Engineering in 2008 and is a fellow of the American Institute for Medical & Biological Engineering and the American Association for the Advancement of Science.

Walt will present the award address before the Division of Analytical Chemistry at the fall ACS national meeting in Boston.