Catherine J. Murphy
Cottrell Scholar and RCSA Board of Directors member Catherine J. Murphy knows better than most that timing is everything; that principle has made her one of nanoscience’s most frequently cited researchers.
In the mid-1990s Murphy, a chemist, led one of the first groups that examined the interaction of nanoparticles with biological systems. This early work was supported in part by her 1996 Cottrell Scholar Award. Then, in 2001, the federal government provided major funding through the National Nanotechnology Initiative, which encouraged many more researchers to focus on the area. They often found Murphy had been there first. In the process she has won numerous additional awards, including:
- 2017 Fellow of the Materials Research Society
- 2015 Elected Member, U.S. National Academy of Sciences
- 2015 TREE Award, Research Corporation for Science Advancement
- 2014 Fellow of the Royal Society of Chemistry
- 2013 Carol Tyler Award, International Precious Metals Institute
- 2011 Fellow of the American Chemical Society
- 2011 Inorganic Nanoscience Award, Division of Inorganic Chemistry, American Chemical Society
Murphy, the Larry R. Faulkner Endowed Chair in Chemistry, University of Illinois at Urbana-Champaign, continues her nanoparticle research today.
“We’re working with gold nanoparticles, doing a lot of surface chemistry on them,” she says. “If we can control what direction molecules are pointing on the surface, then we can control how they interact with bigger molecules, like proteins. And then, if we can understand that, maybe we can understand how they interact with a living cell.”
Her work one day might lead to better drug delivery systems, particularly to attack very early stage cancerous tumors of around one millimeter, the stage at which many tumors somewhat haphazardly begin to lay down blood vessels to feed their growth.
On another front, Murphy and her associates are also exploring possibilities more related to engineering than biology. They are collaborating with engineers in these areas, as well as with experts on the biology side. “It’s a big campus here and there are many researchers doing interesting projects,” she says.
Murphy and her twin sister, Patty, who also works at the University of Illinois as the associate director of research at the Beckman Institute, were born in northern New Jersey. (See the video, "Twin Sister Scientists".) Murphy’s father was a circuit designer for a subsidiary of Bell Labs, and her mother was an executive secretary. Murphy and her twin are the oldest of four siblings, and the first to complete college.
“Growing up, our parents made sure we read a lot,” Murphy recalls. “They would order boxes of books and we would read and read and read. They also encouraged us to play outside and observe things.” Her first memorable experience with science came in third grade, when her class was given monarch caterpillars to care for until they turned into butterflies; the class tagged the butterflies to learn about their migration..
The family moved to the Chicago area when Murphy was in fourth grade. Around that time she developed an interest in the stars. In sixth or seventh grade she kept a notebook with information about constellations, listing magnitudes and distances of their stars from earth. “In eighth grade I had a whole year of chemistry. I thought chemistry was really cool because I liked thinking about things at the atomic and molecular level. We grew little colored crystals and we occasionally set things on fire, so that was good.”
Her first real job, in her junior and senior years, was as a laboratory assistant to the high school chemistry teachers.
Both she and her sister applied to nearby, eventually choosing Illinois. So in 1982 their parents drove their big station wagon downstate and dropped them off in Urbana-Champaign. “Both of us, in our first year as freshmen, started doing undergraduate research,” Murphy says. “I realize now that having that experience was a game-changer.”
Murphy stumbled upon the research opportunity when she sought out a teaching assistant for her freshman advanced chemistry course and found him at his desk in a professor’s laboratory. The TA noticed her interest in all the lab apparatus and asked if she’d be interested in working there. That led to a meeting with the professor, Thomas B. Rauchfuss, who’s still on the Illinois faculty today.
“I started the summer after my freshman year in his lab,” she recalls, “and I did research with him all the way through my whole four years. If I hadn’t done that, I don’t know if I would have known about research at all, because in the undergraduate chemistry curriculum you just do things other people have done.”
Murphy spent a lot of time in Rauchfuss’ lab, often from 8 p.m. to midnight, three nights a week. In the process she managed to be credited as an undergraduate coauthor on two publications. “I really enjoyed the environment,” she says.
She graduated magna cum laude from the University of Illinois in 1986 with two separate bachelor's degrees, one in chemistry and the other in biochemistry.
She went to graduate school at the University of Wisconsin, Madison, where she joined Art Ellis’ research group. Murphy did her Ph.D. thesis on crystalline semiconductors, using laser spectroscopy to study how molecules absorbed to their surfaces. One day in the lab, Ellis mentioned to her that she could be a professor if she wanted to pursue that path. “I hadn’t thought about that,” Murphy says. “And then he said, ‘You know, you should probably do a postdoc.’ ” He suggested she make a list of the top 10 people she’d be interested in, and then they would talk about the list.
“I thought that I wanted to do something a little more bio because, long ago, I’d been interested in biological problems. But I hadn’t done any biological research as an undergrad or a grad student, although I’d been reading the literature.” She made a list of researchers doing interesting work in chemistry, but with biology in the mix, and arranged it alphabetically. The first person on the list was Jackie Barton, who was about to move from Columbia University to the California Institute of Technology. “She had a very high profile in chemistry doing neat stuff with DNA,” Murphy says.
When he saw her list, Murphy remembers Ellis saying, “Jackie Barton? Oh, I know her. Let me give her a call. Step out of the room.” A few moments later he called her back in, saying Barton wanted to talk to her. She got the postdoc then and there, without any formal application.
Murphy’s first task with Barton was to write a proposal to investigate how well the DNA double helix could transport charge. “This is back in the 1990s,” Murphy says. “It was a new thing, and it’s still kind of a weird thing to think about.”
The proposal was funded, which meant Murphy could support herself as a postdoc. She and her new husband, Bob Murphy, a young mathematician she’d met when they were both undergraduates at Illinois, went out to Caltech. Her research there led to a paper in Science. The work was controversial, due to the many controls and difficulties involved in measuring charge along the double helix.
Eventually, however, Barton and her associates discovered charges can travel efficiently across long molecular distances through the DNA helix “while maintaining an exquisite sensitivity to base pair π-stacking. Because DNA charge transfer chemistry reports on the integrity of the DNA duplex, this property may be exploited to develop electrochemical devices to detect DNA lesions and DNA-binding proteins,” according to the conclusion of a recent paper coauthored by Barton.
By the time her postdoc time was up, Murphy had decided she liked the academic life and decided to apply for a teaching positon. Her husband, who had been taking a few math classes “for fun’’ while Murphy worked with Barton, was willing to go wherever she wanted. They were both hired by the University of South Carolina, Murphy in the Department of Chemistry and Biochemistry and Bob in the Department of Mathematics, where he worked as a TA as he finished his M.S.
They spent 16 years in South Carolina. “We both had vibrant jobs there, plus I really liked the department,” Murphy says. “They were very friendly, very open and they encouraged some avant-garde chemistry, which is not widely known.”
Murphy, intrigued by the work she’d done with Barton, continued to study the physical properties of DNA – “how you bend it and what would that do, how you can measure it. I was also interested in some of the molecules we made to bind to DNA.” She began this work as a new faculty member in 1993, as interest in nanomaterials was just beginning to grow.
“What I was interested in, fundamentally, was thinking about placing a a biological molecule, on a little ball of material, measure how the material might deform the molecule, and whether that might have any kind of impact. And of course we know that DNAs are all balled up into chromosomes in live cells, so I thought about trying to make artificial chromosomes and control gene expression in that way.”
Thus, she began designing experiments looking at the interface of biological molecules with nanomaterials. In retrospect, those experiments were well ahead of their time. “And, actually, I still do that today,” Murphy says.
“What I started working on became a pretty productive vein of inquiry. We soon realized we needed to make our own nanoparticles.” They settled on gold. “The synthesis is much easier than all the complex molecules I was making with Tom. You basically take a gold salt and reduce it to the metal gold under controlled conditions where you can control the size and shape of the resulting gold nanoparticles. We started doing that, and we’re still doing that now.”
Meanwhile, the University of Illinois invited Murphy back periodically to give talks about her research, and after a 2007 visit, Tom Rauchfuss, her undergraduate mentor, called her with a job offer. Murphy and her husband, who also grew up in the Chicago area, moved back in 2009. Bob found a job in the math department and Murphy continued her research.
Murphy is also passionate about teaching and has never missed a semester since becoming a professor. “I do one class a semester, and that’s going to be true for almost anybody who’s a Cottrell Scholar,” she says, adding she especially enjoys teaching freshman chemistry. “The material is fun because it’s a lot of fundamental stuff every chemist should know, and freshmen are very enthusiastic. They want to do good things.” And besides the occasional graduate level course, she also teaches more exotic classes. Illinois is a big engineering school, and she provided the chemist’s view for a Bioengineering Department class on cancer nanotechnology for three years.
Chemistry is not only Murphy’s profession, but her hobby as well. Her “leisure-time” pursuit involves working on the widely used textbook, Chemistry, the Central Science, also known by the names of the original authors, Brown & LeMay. The book is in its 14th edition, and Murphy, as one of the six current authors, spends many of her evenings working to come up with material for an updated edition, which comes out every three years.
