Argonne chemist Tijana Rajh and nanoscientist Jorg Maser
Innovators, 3
December 2009 / January 2010
Volume 7 Number 6
It was a watershed moment. When Argonne nanoscientist Tijana Rajh visited the laboratory of her mother's friend during her childhood in the former Yugoslavia, she knew that scientific research held a special fascination for her. "I fell in love with it," Rajh said. "There was absolutely no question what I was going to do with my life. And then when I came here," she added, smiling, "I was hooked."
It was more common, she said, for women to pursue careers in science in Yugoslavia than in the United States, where she met Marion Thurnauer, the only female Ph.D. staff member in Argonne's chemistry division. Encouraged by Thurnauer's dedication to increasing the number of women in the laboratory, Rajh rose to become leader of the nanobio interfaces research group at Argonne, and this summer won the third annual Innovator Award from the Chicago chapter of the Association of Women in Science. The award honors contributions to science in the Chicago area, and recognized Rajh for her studies of semiconductor nanoparticles, a field with applications from solar power to cancer research.
While finishing her undergraduate physical chemistry degree at the University of Belgrade, Rajh was invited by a professor to join a research project attempting to split water into hydrogen and oxygen molecules for fuel purposes. That project motivated Rajh's continuing interest in semiconductor nanoparticles—€”tiny particles made from materials which form the heart of modern electronics. Their photoactivity and stability is exactly what makes them good for many uses, from pollutant cleanup to medical imaging.
Rajh and the research team noticed that the particles of the same chemical composition appeared in different colors as researchers shrunk them smaller and smaller. Nanoparticles can change color, and other characteristics, with size: a quirk useful for many applications. "When you see it for the first time, it's so amazing," Rajh said. Together with her advisor Olga Micic and collaborator Art Nozik at the National Renewable Energy Laboratory, she authored one of the first three papers ever written about colloidal quantum dots in 1985.
Thurnauer brought Rajh to Argonne in 1994, where she began studying how to use nanoparticles in a variety of applications: remove heavy metal pollutants from the environment, write data to nanocircuits in computers, and link nanoparticles with biological materials. "At the time she was hired at Argonne, and for the next eight years, she was the only female Ph.D. staff member of Argonne's chemistry division," Rajh said of Thurnauer. "That experience prompted her to encourage broader searches for women to be represented in the Argonne job candidate pool."
In the Center for Nanoscale Materials, Rajh works with particles made of the semiconductor titanium dioxide (TiO2), which is white. When combined with organic compounds such as vitamin C or dopamine, which are also white, the TiO2 nanoparticles turn a brilliant red—€”indicating that the two materials are interacting at the molecular level. This discovery allowed her and her team to electronically link TiO2 particles with DNA and other biological molecules, opening new biomedical possibilities.
One of the Rajh's team members and colleagues, Elena Rozhkova, is working to apply the particles to cancer treatment. "She marks glioma cancer cells with TiO2 particles," Rajh explained, "and doctors could use light of a certain energy to destroy only those marked cells, leaving healthy cells intact."
Rajh received her Ph.D. in 1986 from the University of Belgrade. Prior to working at the center, she joined Argonne's chemistry division in 1996 and has been a prolific researcher, co-authoring six papers in 2008 alone.
She is the third scientist to be recognized by the Association for Women in Science, a nonprofit organization dedicated to advancing women in the field of science. The group formed in 1971 and has since expanded nationwide. The Innovator Award recognizes achievements in science in the Chicago area.
The CNM at Argonne is one of the five DOE Nanoscale Science Research Centers (NSRCs), premier national user facilities for interdisciplinary research at the nanoscale. Together the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities to fabricate, process, characterize and model nanoscale materials, and constitute the largest infrastructure investment of the National Nanotechnology Initiative. The NSRCs are located at DOE's Argonne, Brookhaven, Lawrence Berkeley, Oak Ridge and Sandia and Los Alamos national laboratories.
Louise Lerner is a writer at Argonne National Laboratory.
Copyright © 2012 | Innovation America