|Fluorescent dye synthesis (Yu and Matthew)|
|Nanosecond laser flash photolysis|
Our group is broadly interested in fabricating and studying new polymers that have utility as stimuli-responsive materials. These materials are made by co-polymerizing a fluorescent dye with a variety of styrene or acrylamide co-monomers. Fundamental photophysics are used to tailor these materials for a response of choice. For example, to map temperature distributions in real time on any surface or object, we are fabricating polymeric coatings that exhibit exciplex or excimer formation. This phenomenon is characterized by a two-color emission. By imaging the intensities of each color, as a function of spatial coordinate, the precise temperature on each point of the object can by quantified and monitored in real time. At the same time, we are interested in developing polymeric coatings that exhibit a time-temperature response for smart packaging applications (like when has your milk jug been left too warm too long!). These materials take advantage fluorescence quenching, which can be thermally reversed via a chemical reaction in the polymer (i.e. your milk jug lights up under black light when it has risked spoiling!).
Photochemical Probes of Macromolecular Structure.
Complemenary methods of transient laser spectroscopy and traditional bioanalytical methods are used to investigate the photocleavage and photomodification of proteins and DNA. Research projects begin with the synthesis of functionalized aromatic imides and diimides designed to photoinduce a specific kind of damage (cleavage, cross-linking, affinity labeling, etc.). Next, the photophysical and redox properties are assessed using transient and steady-state spectroscopy, along with electrochemical methods. Transient absorption spectroscopy is used to identify the early photochemical events with viable targets (nucleic acids and peptides or proteins). Finally, traditional bioanalytical methods are used to correlate the early photochemical events with the modified macromolecules. The complementary approach offers a fundamental understanding into the development of new small molecules that can be light-activated and serve as static and dynamic probes of macromolecular structure.