COLUMBIA - The long, thin fibers and tubes on the benches in Xudong Fan's lab might look like simple pieces of glass, but Fan and his group are trying to use them to detect a variety of substances - all the way down to a single molecule.
The lab's work has turned heads. Last month, Fan, an assistant professor of biological engineering at MU, received the first part of a five-year, $400,000 grant from the National Science Foundation as part of that group's Faculty Early Career Development program, or CAREER.
Fan's research focuses on opto-fluidic ring resonators, a type of sensor in which light travels along the wall of a small glass tube, or capillary, containing a liquid or gas to be analyzed.
The capillary's properties allow the light to make thousands of loops around the sample. This allows much more of the light's energy to interact with the sample than in other types of light-based sensors, in which the light and the sample might only meet one time or a few times.
Fan said the technology has several applications, including environmental testing and new kinds of lasers as well as detection of cancer, other diseases and explosives.
Jon Suter, a doctoral student in biological engineering, has worked for the past three years in Fan's lab - an environment he described as fast-paced.
"He sets the bar high for the rest of us," Suter said.
William Schultz, a program director at the National Science Foundation's Division of Chemical, Bioengineering, Environmental, and Transport Systems, said the award is intended to help assistant professors in their first few years as faculty members.
"They're at the formative stage of their career," he said.
Fan's CAREER award is for his work on using the sensors along with fluorescence resonant energy transfer - a method that allows researchers studying diseases to detect whether certain types of molecules bind with each other.
"Binding is really important," Fan said. "It can prevent disease, or it can cause disease."
The technique relies on "tagging" molecules with fluorescent markers of different colors. When two of these molecules bind with each other, one marker transfers energy to the other, which changes how much of each color is observed.
Right now, though, researchers can only detect these differences with relatively large or concentrated samples, which can be expensive.
Fan said he hopes his device can allow people to observe smaller differences, which in turn would work with smaller, less concentrated samples.
"A little, tiny change would be important," Fan said.
Fan said his technology would allow researchers to use samples of only a few nanoliters - billionths of a liter - instead of samples tens of thousands of times that large, which they use now.
Fan's group is trying to advance the technique to the point that it can detect single molecules, which he said is "probably five years down the road."
Even though his latest grant kicked in earlier this month, he said the group went ahead and started working on single-molecule detection a few months ago.
"We don't want to wait," he said.
Before coming to MU in 2004, Fan worked on biological sensors for 3M, which Suter said brings a valuable perspective to the lab.
"He has a very well-grounded, very realistic view of what drives your research toward a practical end," Suter said.
That perspective is proving particularly useful since the CAREER award isn't just for research. It's also for education, and Fan's already got plenty of ideas on that front.
He used department funds earlier this year to get a head start on a program to bring people from industry, including executives and senior research scientists, to speak to his students and answer their questions.
Fan explained the connection with industry allows the companies to meet with students and see what they're working on.
"We want them to know our students," he said.
Fan said he also met with a teacher from Hickman High School in July in an effort to give high school students the opportunity to work in a lab and "do real bench work."
"I really want to promote these programs," Fan said.