Ultrafast Dynamics of Biomolecules, Nonlinear Optics
B.S. Chemistry, University of Nebraska at Omaha, (1999); Ph.D. Physical Chemistry, Kansas State University (2002); Postdoctoral Fellow, University of Rochester (2002-2003); Postdoctoral Fellow, Northwestern University (2003-2004); Postdoctoral Fellow, University of Chicago, (2004-2007)
Light driven electron and energy transfer processes in proteins and nucleic acids are the main focus of our research. We are most interested in dynamics that occur on time scales less than a nanosecond. Energy transfer in photosynthetic systems, DNA photodamage and electron transfer in photoactive enzymes (e.g. photolyases, cryptochromes) are examples of such processes. The general goal of our experimental work is to correlate the time evolving charge distributions associated with biological photochemistry to particular sites and structural motifs (i.e. a real space picture of the dynamics). Our experimental work is complemented by molecular dynamics simulations of the photochemistry.
Nonlinear laser spectroscopies are the common tool used in our research projects. These experiments effectively synchronize photoinduced events in a large population of individual molecules and track their evolution with femtosecond time resolution. We are particularly interested in applying novel higher-order spectroscopies that correlate electronic motion to nuclear structure in enzymes by measuring vibrational spectra of selected individual residues. The development of broadband sources of ultraviolet light will be important for enhancing signal generation at specific sites in these complex systems.
J. W. Womick, S. A. Miller, A. M. Moran "Probing the Dynamics of Intraband Electronic Coherences in Cylindrical Molecular Aggregates," J. Phys. Chem. A, 113, 6587-6598, (2009).
J. W. Womick, S. A. Miller, A. M. Moran "Correlated Exciton Fluctuations in Cylindrical Molecular Aggregates," J. Phys. Chem. B, 113, 6630-6639, (2009).
S. A. Miller, J. W. Womick, J. F. Parker, R. W. Murray, A. M. Moran "Femtosecond Relaxation Dynamics of Au25L18- Monolayer-Protected Clusters," J. Phys. Chem. C, 113, 9440-9444 (2009).