Dr. Monty Fetterolf: Dr. Fetterolf’s research involves the broad topic of solute/solvent interactions. These interactions are investigated using probe solute molecules that respond spectroscopically to the solvent environments. A better understanding of solute/solvent interactions may lead to spectroscopic solute indicators of solvent properties that can be used during a chemical process when monitoring the solvent is important.
One group of research students work with methylene violet and its analogs which display solvatochromism—the change in solution color as the solvent is changed. In these cases, the solvent can respond in a nonspecific manner to solvent change, seen as a correlation with solvent dielectric constant, or in a specific manner, seen as a correlation with the solvent’s Acceptor Number—a measure of lone electron pair sharing ability. The maximum in absorption measured with the Perkin Elmer Lambda-35 UV-Visible Absorption Spectrometer is used to monitor the color changes during solvatochromism. Students obtain wavelength maxima in different solvents and also investigate the temperature dependence of this phenomena. A collaboration with Dr. Rowe allows students to explore the use of computation as a tool in understanding solute/solvent interaction geometries.
A second group uses Raman vibrational spectroscopy to measure the specific interactions that the molecule ethyl-4-dimethylaminobenzoate (EDAB) and its analogs have with solvent. Several Raman spectroscopic peaks shift to different energies as a result of strong specific interactions of the ester functionality of EDAB with the various solvents. Presently, we are exploring structural analogs of EDAB to see what physical characteristics of the probe molecule lead to the greatest peak shifts in various solvents. Once the best probes have been selected, we plan to explore mixed solvent systems looking at how peaks respond to changes in solvent mole fraction.
Dr. Chad Leverette: Dr. Leverette and his students have been very successful in designing new sensor materials at the nanoscale using several methods of nanofabrication, including physical vapor deposition. The new sensor materials are used as substrates for surface-enhanced vibrational spectroscopy (i.e., SERS and SEIRA) to detect and differentiate trace amounts of various radioactive environmental contaminants at the Dept. of Energy Savannah River Site.
Dr. Kenneth Roberts: Dr. Roberts joined the faculty in 2015. As a biochemist and enzymologist, he is interested in the underlying principles that govern the catalytic reactions of enzymes. His current projects are centered around the enzyme, 2,4’-dihydroxyacetophenone dioxygenase (DAD), which catalyzes the cleavage of a unique carbon-carbon bond. He and his students are currently investigating the steady-state kinetics of the DAD reaction including temperature- and pH-dependence and the possibility of inhibition by the reaction product. Upcoming projects include mutating the enzyme and altering the substrate to determine the chemical roles of active-site amino acids and substrate functional groups, respectively. Work on this project includes many techniques across several fields including biochemistry, analytical chemistry, organic chemistry, molecular biology and microbiology. Students in his lab can gain hands-on experience with measurement and evaluation of reaction kinetics and isotope effects, synthesis of mechanistic probes, UV-visible absorbance spectroscopy, cell culture, gene mutagenesis, and protein expression and purification.
Dr. Gerard Rowe: Dr. Rowe, who joined the faculty in Fall 2010, synthesizes novel inorganic complexes which have been modeled after the active sites of enzymes. These complexes will then serve as stable catalysts in important processes such as those that might be used in fuel cell technology.