Graduate Research

Brian T. Cooper
Associate Professor
Bioanalytical Chemistry
B.S.: Purdue University
Ph.D.: University of Arizona
Post-doc: (NIH Fellow) Iowa State University

ORAU Junior Faculty Enhancement Award
NSF Faculty Early Career Development (CAREER) Award

Bioanalytical Chemistry — protein analysis by:

  • capillary/channel electrophoresis;
  • ultrasensitive fluorescence detection and imaging;
  • electrospray and MALDI mass spectrometry.

My research group primarily uses capillary electrophoresis (CE) to analyze and characterize proteins. Capillary electrophoretic separations of protein “charge ladders” (otherwise pure proteins with intrinsic or induced charge heterogeneity) allow us to estimate the net charge and hydrodynamic radius of proteins in solution. We also study ligand binding to proteins using “affinity capillary electrophoresis” (ACE), which exploits the accompanying change in protein electrophoretic mobility. Combining charge ladders and ACE allows us to characterize overall conformational changes caused by ligand binding. And with laser-induced fluorescence (LIF) detection, we can study the conformational behavior of fluorescently labeled proteins under simulated intracellular conditions—especially in the presence of high concentrations of other macromolecules.

We also have an active collaboration with a group in the Department of Bioinformatics and Genomics. We are using a variant of ACE called “CEMSA” (capillary electrophoretic mobility shift assay) to detect binding of transcription factors (TFs) to synthetic, fluorescently labeled DNA probes. We use this technique to experimentally validate predicted TF binding site sequences. After screening by CEMSA, we can identify affinity-purified TFs using mass spectrometry.

Bernadette T. Donovan-Merkert
Analytical Chemistry
B.S.: Duke University
Ph.D.: The University of Vermont
Post-doc: Dartmouth College; The University of Texas at Austin

National Science Foundation
Camille and Henry Dreyfus Foundation
Petroleum Research Foundation
Research Corporation

My group focuses on electron-transfer reactions of organometallic complexes. By oxidizing or reducing these compounds we often generate species that undergo interesting reactions or form complexes in unusual oxidation states. In many cases redox activation of organometallic complexes accelerates known reactions of these compounds, activates otherwise inert complexes, or allows reactions to occur under milder conditions. We study the reactions and their products using electrochemical methods and other instrumental techniques including, but not limited to, NMR, IR, ESR and GC/M.S..

Markus Etzkorn
Associate Professor
Organic Chemistry
Pre-diploma: University of Freiburg (Germany)
Diploma: University of Feriburg (Germany)
Dr. rer. nat. (Ph. D.): University of Freiburg (Germany)
Postdoc: USC – Loker Hydrocarbon Research Institute Unusual structures (fullerenes, dodecahedrane, fluorinated graphite…) display often extraordinary properties that reward organic chemists for all the effort taken to achieve a challenging synthetic goal. Using contemporary tools of synthetic organic chemistry my group explores the potential of new (functionalized) hydrofluorocarbons as precursors to applied materials. In addition photochemical conversions of suitable hydrofluorocarbons could ultimately lead to highly strained cage systems with unique physicochemical properties.

Daniel S. Jones
Associate Professor
Physical Chemistry
B.S.: Wake Forest University
Ph.D.: Harvard University
Post-doc: State University of New York at Buffalo; Naval Research Laboratory, Washington, D.C.

X-ray Crystallography: Determination of molecular structures by X-ray crystallographic methods.
Structure determinations are carried out on compounds of interest in a variety of research endeavors; the particular compounds studied often depend on the immediate research interests of faculty colleagues here and elsewhere. Compounds recently studied include those of interest in 1) thin-film microelectronics technology, 2) image enhancement in Magnetic Resonance Imaging, and 3) the search for cancer therapy agents.

Marcus Jones
Assistant Professor
Physical Chemistry
B.A.: Oxford University
Ph.D.: Cambridge University
Post-doc: University of Toronto

We are interested in understanding photo-induced excitation dynamics in colloidal semiconductor nanocrystals (NCs). These colloidal materials hold tremendous potential for low-cost processing and high-efficiency solar energy conversion. This is principally due to their size-tunable absorption thresholds and high photo-stability. We aim to develop models of the complex electronic interactions in nanoscale materials between intrinsic photo-generated states and the local environment. To do this we combine efforts in nanocrystal synthesis, time-resolved spectroscopy and development of semi-empirical models of nanocrystal photo-excitation dynamics.

Our current focus is on carrier trapping and light-induced charge transfer reactions in colloidal nanocrystals. We want to understand the processes that promote charge separation in these materials to enable development of new nanocrystal-based materials with greatly improved characteristics for photovoltaic applications.

Joanna K. Krueger
Associate Professor
B.A.(ACS): Kalamazoo College
Ph.D.: Princeton University
Post-doc: (NIH/NRSA Fellow)
U. T. Southwestern Medical Center
Los Alamos National Laboratory

Research Corporation- Cottrell College Science Award
ORAU Junior Faculty Enhancement Award
North Carolina Biotechnology Award

Biophysical Chemistry
My laboratory is interested in obtaining structural information on biomolecular associations using the techniques of small-angle X-ray and neutron scattering, chemical cross-linking with peptide analysis by Mass Spec, selected-site mutagenesis and spectroscopy (FTIR, CD, UV-VIS). We will use these data to build molecular models of protein:protein complexes and thus, to provide new insights into the molecular basis of protein interactions.
Currently, we are looking at a protein, gelsolin, that when activated, through increases in intracellular calcium, binds to the cytoskeletal actin and regulates actins’ ability to self-associate. This regulation results in cell shape changes essential to the proper functioning of the cell. By studying the structure of the molecular complex between actin and gelsolin, we will provide key insights into molecular basis for several disease states related to improper functioning of the cell, such as cancer.

Craig A. Ogle
Organic Chemistry
Regional Analytical Chemistry Laboratory
B.S.: Otterbein College
M.S.: University of Arizona
Ph.D.: University of Arizona
Post-doc: University of Lausanne, Lausanne, Switzerland

My research has centered on the preparation, reaction and structure of carbanionic species. We are currently preparing organometallic reagents as chiral auxiliaries for organic synthesis. We are preparing functional monomers for preparing functional polymers. We are using the rapid injection NMR technique to help understand the mechanisms for organometallic conjugate addition reactions.

Jordan C. Poler
Associate Professor
Physical Chemistry
B.S.: State University of NY at Brockport
Ph.D.: University of NC at Chapel Hill
Post-doc: Princeton University

Materials: Fundamental studies of complex systems at the nanoscale with regard to applications of materials at the macroscale. Complex systems exist at surfaces, interfaces and thin films. The experimental techniques that I use to study these systems are both optically and electronically based. Scanning probe microscopies are the work-horses of my research. In particular, the scanning tunneling microscope (STM) and the newly developed scanning thermopower microscope (STPM) are central in my studies of surfaces and interfaces. The complex systems that are of most interest to me are in the areas of both; “hard” materials (e.g. semiconductors and metals) and “soft” materials (e.g. self-assembled monolayers, biologically interesting molecules and Langmuir films).

Daniel Rabinovich
Inorganic Chemistry
B.S.: Catholic University (Lima, Peru)
Ph.D.: Columbia University
Post-doc: Los Alamos National Laboratory

The challenge and excitement of making new compounds and discovering unusual reactivities—the ultimate goals of most synthetic chemists—are incomparable. Research interests in the “DR group” are in synthetic and structural inorganic, bioinorganic, and organometallic chemistry, including the coordination chemistry of multidentate sulfur- and selenium-donor ligands and the preparation of model compounds for metalloenzymes, as documented in some 60 peer-reviewed publications. In particular, ongoing projects include the use of bis(thioether)silanes to synthesize cadmium, mercury, palladium, platinum and coinage metal complexes that display unusual structural features (e.g., low coordination numbers), interesting physical properties (e.g., luminescence) or unexpected biological activity. In a similar vein, bis(mercaptoimidazolyl)alkanes and related bis(thione) and bis(selone) ligands are being used to prepare a range of interesting species, including synthetic analogues of sulfur-rich copper proteins such as methanobactin.

John M. Risley
B.S.: Ball State University, Muncie, Indiana
Ph.D.: Purdue University, West Lafayette, Indiana.
Post-doc: Purdue University, West Lafayette, Indiana

I. Studies of Glycosylasparaginase, the Enzyme Involved in the Most Common Disorder of Glycoprotein Degradation
II. The 18 O Isotope Shift in NMR.

Tom Schmedake
Associate Professor
Inorganic Chemistry
B.S.: Knox College
Ph.D.: University of Wisconsin
Post-doc: UC San Diego

My research interests ultimately seek to use synthetic chemistry to modify the properties of advanced materials and to study systems in which advanced porous materials incorporating photonic confinement effects are used to alter the chemical properties and reactivity of intercalated molecules.

Jerry (Jay) Troutman
Assistant Professor
B.S.: East Carolina University
Ph.D.: University of Kentucky Medical Center
Post-doc: Massachusetts Institute of Technology

Bacterial Polysaccharides: Here we will attempt to understand the biochemistry of polymeric sugars called polysaccharides that coat the surface of specific bacteria, and play an important role in interactions between symbiotic gut microbes and their mammalian hosts.

Mammalian Isoprenylation: We are also interested in the role of the downstream processing of prenylated proteins in particular the enzymes involved in this important biological process, and the possible targeting of these proteins for the treatment of diseases such as cancer.

Juan Luis Vivero-Escoto, Ph. D.
Assistant Professor
Organic/Materials Chemistry

Research in our group focuses on the design, and synthesis of novel hybrid inorganic-organic materials for a wide variety of applications, predominantly in biomedicine, renewable energy, and catalysis. Our approach is multidisciplinary, interfacing chemistry, biology, and material science. By its very nature our research will provide an excellent training environment for undergraduates, graduate students and postdoctoral research fellows. Students in our group are exposed to and trained in synthesis and characterization of small molecules (organic and inorganic alike), polymers, and nanomaterials. Specific techniques they learn include, but not limited to, nuclear magnetic resonance spectroscopy (NMR), absorption and emission spectroscopies, dynamic light scattering (DLS), transmission and scanning electron microscopies (TEM and SEM); and basic cell culture and characterization techniques.

Listed below are the three main research projects we are pursuing: – Multifunctional hybrid nanoparticles as a delivery platform for photodynamic therapy and diagnosis. – Boronic acid-based nanoscale coordination polymers as novel metal/covalent organic frameworks with potential applications in drug delivery. – Hierarchically assembled titania-phosphonate dendrimer-encapsulated nanoparticles with potential application in photocatalysis.

Michael G. Walter
Assistant Professor
Organic/Materials Chemistry
B.S.: University of Dayton
M.S.: Portland State University
Ph. D.: Portland State Univeristy
Post-doc: California Institute of Technology

Research in the Walter lab focuses on the synthesis and integration of organic conjugated polymers and dye molecules for solar energy conversion applications. Nature accomplishes the task of solar energy conversion by using molecular systems to direct photoinduced reactions that ultimately store solar energy in the form of chemical bonds. We attempt to mimic these processes by designing materials that absorb solar photons and efficiently convert them into electricity or fuels such as hydrogen. Organic semiconductors are desirable for these applications because they offer the potential for an inexpensively processed, lightweight, and flexible photoactive material. Unique to this effort is the development of new porphyrin and corrole macrocyclic dyes that exhibit interesting optoelectronic properties.

Characterization of the fundamental photoinduced electron transfer properties of synthesized materials is conducted using photoelectrochemical techniques, spectroscopy, and device integration. New, promising light absorbing systems are studied in polymer solar cell and in dye-sensitized TiO2 solar cell configurations. In addition, efforts are made to tune photoinduced electron transfer mechanisms at organic and inorganic interfaces through molecular design and nanostructure. One of the ultimate goals of these efforts is the design of an artificial photosynthetic system that uses inexpensive molecular semiconductors and catalysts to convert water and carbon dioxide into usable fuels such as hydrogen and methanol. The advancement of this field rests on the discovery new organic semiconductors, a field where synthetic organic chemists can contribute in a significant way.