Students engage in collaborative research that could help combat bioterrorism

RELEASED: July 10, 2008

DANVILLE, KY—During any given summer, Centre College students can be found collaborating with their professors on research projects exploring a range of exciting subjects. This summer, rising juniors Emily Green and Sarah Steele have been engaged in research with Dr. Jeff Fieberg, assistant professor of chemistry, in the area of nanoscience. The group has fabricated a nanoscale biosensor that detects a particular molecule in an aqueous (watery) solution, with an ultimate goal of developing a sensor that could detect a specific bioterrorism molecule in the water supply. 

"We generally have a seven to eight hour work day, five days a week," Green says. "We mix chemicals, fabricate membranes, sense model terrorism agents and occasionally help Dr. Fieberg with his chemical demonstration show."

All student research collaborators are provided with a $2,500 stipend and are credited in all published materials as co-researchers.

"There are weeks on end where it seems that nothing we are doing is working," Steele says. "Although this could seem discouraging, and sometimes it is, I think waiting and working hard to see a certain effect only makes it mean so much more when it actually happens."

Steele, Greene and Fieberg are not the only ones working on this project. The research began as a collaboration in 2006 with Charles Martin '75, professor of chemistry and the director of the Center for Research at the Bio/Nano Interface at the University of Florida.

"I spent my first CentreTerm learning these fabrication and measurement techniques in Martin's laboratory," Fieberg says. "And so, for the next two years, I've been teaching Centre students these techniques. We've continually built our knowledge the past few summers, and this summer, we've made a breakthrough with publishable results." 

In the 2008-2009 academic year, Green and Steele will continue moving the project forward (along with Goldwater Scholar Benjamin Gowen '09) as part of an independent study with Fieberg. They will then present their research at two American Chemical Society (ACS) meetings next year—SERMACS (Southeastern Regional Meeting of the ACS) in Nashville in November and the National ACS meeting in Salt Lake City, Utah, in March.

For more information on collaborative research at Centre, click here.

To learn more about the specifics of their research, read further for Fieberg's explanation.

"To make the biosensor, the Fieberg research group begins with a very thin sheet of polycarbonate, the same plastic of which CDs are made (it’s like Saran Wrap, just not sticky). The plastic membranes come from Germany with ion damage tracks in them. Extremely fast moving gold ions are slammed through the plastic, leaving tracks that are essentially an atom wide.

"Green and Steele then make these tracks into conical holes, or pores, by chemically etching them in a basic (sodium hydroxide) solution (see Fig. 1-3). The cones are 500 nanometers wide at the base and approximately 10-70 nanometers wide at the tip. The inside of the pores are then gold-plated via a three-step process.

"A molecular recognition agent (MRA) is attached to the gold. This MRA will selectively bond to the specific molecule to be detected, called the analyte. The desired final tip size of the conical pore should be the size of the molecule to be sensed. The sensor works by applying a voltage and measuring the current flow in a salt solution through the membrane. If the analyte is present, it will bind to the MRA and clog the pores. This clogging is observed as a drop in the current within the device. 

"This summer, the analyte has been fluorescently tagged streptavidin. Following sensing, the streptavidin (and therefore shape of the pores) can be seen with fluorescence microscopy (see Fig. 4). The orange circle highlights one nanopore (green ring) that displays fluorescence from streptavidin bound to the MRA, which is bound to the gold nanotube." 

- end -

Founded in 1819, Centre College is ranked among the U.S. News top 50 national liberal arts colleges. Consumers Digest ranks Centre No. 1 in educational value among all U.S. liberal arts colleges. Centre alumni, known for their nation-leading loyalty in annual financial support, include two U.S. vice presidents and two Supreme Court justices. For more, visit http://www.centre.edu/web/elevatorspeech/

For news archives go to http://www.centre.edu/web/news/newsarchive.html.