October 18, 2010
By Benjamin White

Dr. Alexander Govorov of Ohio University's Department of Physics and Astronomy gave a lecture on chiral nanostructures at Baker Center Wednesday as part of the College of Arts and Sciences' New Professor Lecture series. Dr. Govorov, a Russian native, recently earned his full professorship after almost a decade at OU, where he authored many of his 120 peer-reviewed articles.

Dr. Govorov, a member of NQPI, explained the basics of his theoretical work with chiral nanostructures, a new branch of nanotechnology that could have a profound and lasting impact on optical devices. Chirality, he explained, is the “handedness” of nanostructures when a nanostructure is non-superposable with its mirror image, not unlike left and right hands. A prominent example of a chiral object is the right-handed DNA strand.

The important biomolecules (proteins, DNA, sugars) are chiral by nature, and the stream of photons forming a beam of light can be manipulated into a chiral form as well. A microscopic beam of light can be chiral, he explained, if the electric field of the photons moves in a spiral pattern. When chiral light is passed through a solution containing chiral material, scientists can tell whether the structure of molecules in a solution (e.g. proteins) has a clockwise or counterclockwise nature to it by examining how the beam of light reacts with the solution containing chiral molecules.

This effect, however, can typically be seen with ultraviolet light. Seeing this effect with visible light would be easier and would open the door for new optical technologies.

Dr. Govorov proposed and modeled a system that does just that.

His proposal uses a gold nanocrystal, a giant (in molecular terms) cluster of gold atoms, and attaches it to a chiral protein. After putting the nanostructure into a solution, scientists would pass visible chiral light through the liquid. Govorov predicts the chiral light would change, making it easy for scientists to tell exactly which chiral proteins were in the solution. This effect has recently been confirmed experimentally by a group at Air Force Research Labs in Dayton and should have important ramifications on cutting-edge optical sensors and other nanotechnology.

Dr. Govorov obtained his Ph.D from the Institute of Semiconductor Physics at Akademgorodok in Russia and has been at Ohio University since 2001, when he moved to Athens as a visiting professor.

The New Professor Lecture Series has highlighted the research and creative work of each new professor in the College of Arts and Sciences for five years. Lectures are held on Wednesdays at 4 p.m., and video recordings of each lecture will be posted to Ohio University's Web site.