This award supports a two-year collaborative research project between Professor Therese Cotton of Iowa State University and Professor Katsume Niki of Yokohama National University. The objective of the research is to develop methods for enhancing the heterogeneous electron transfer process at the electrode surface. An understanding of those factors that are important for reversible electron transfer could result in the preparation of bioelectronic devices based upon the photosynthetic components. Professor Cotton will continue development of monolayer methods and use resonance Raman spectroscopy (RR) and surface-enhanced resonance Raman scattering (SERRS) to characterize the monolayers. Professor Niki will develop electrode surface modifications for improving electron transfer kinetics. The adsorbed monolayers will then be characterized by electroreflectance spectroscopy. Also involved in the project is Professor Robert Uphaus of Iowa State University. The U.S. and Japanese groups have complementary expertise in the characterization of proteins and other electroactive species on electrode surfaces. The use of RR and SERRS in the U.S. component of the research will provide vibrational spectra of the various redox active species. The Japanese group will determine electroreflectance spectra on the same systems. Measurement of optical changes in the pigments as a function of potential will be extremely valuable in those cases where the vibrational spectra overlap strongly. Moreover, the use of optical measurements may enable the accurate determination of the midpoint potential of BChl and BPheo in the reaction centers. This information is very important with respect to the mechanism of photoinduced electron transfer.
