Chemistry People: Faculty by Name:

Research Interests
Bioanalytical Chemistry — Antibody-Antigen Equilibria in a Field of Magnetic Forces: Protein Micro-Array Sensors
Electrochemistry — Dynamic Properties of Amphiphiles at the Air/Water Interface

Our research concerns two parallel projects. In the bioanalytical area, our long term goal is the design of protein and DNA micro-array sensors. At a fundamental level we ask whether application of mechanical forces can be used to shift the position of chemical equilibria such as those governing antibody-antigen binding. We also investigate the effects of special confinement on such equilibria.

In the area of interfacial chemistry we investigate dynamic behavior of monolayer assemblies at liquid/gas and solid/liquid interfaces. We are interested in understanding how composition and structure of monolayer assemblies affect the dynamics of such processes as long range electron tunneling, lateral molecular diffusion and vectorial proton transport. Our underlying goal is to address issues relevant to the behavior and functioning of biological membrane systems. For example, Langmuir techniques, Brewster angle microscopy (BAM), 2D electrochemical methods, and electron spin resonance spectroscopy are used to study lateral mobility of lipids at the air/water interface in order to understand physical properties of lipid monolayers and to probe the water liquid-vapor interfacial region. We want to learn about the dynamic properties of this important interfacial region and to understand how they differ from the properties of bulk water. Likewise, we want to understand what types of interactions determine phase behavior and the lateral dynamics of lipid monolayer films on the water surface. How does their mobility depend on their immersion depth, surface density and on the physical properties of the interfacial water region?

Kinetics of long-range electron tunneling has been another area of our research. We developed new experimental techniques to investigate the intervening medium effects on the strength of electronic coupling between electron donor and acceptor. In one approach, our measurements involved electrochemical techniques using expanding mercury drop electrodes as well as Hg-Hg tunneling junctions incorporating monolayer films of controlled molecular structure. In a different approach, kinetics of lateral electron hopping in Langmuir monolayers of redox centers is investigated with line micro-electrodes directly at the air/water interface. BAM and grazing incidence X-ray diffraction are used to characterize the morphology and structure of such 2D assemblies. These data are then used to interpret 2D electrochemical measurements in terms of the distance and the orientation dependence of the individual electron transfer events between the adjacent redox centers.

Biography
Born 1951; M. Sc. Warsaw University (1974); Ph. D. Southern Illinois University at Carbondale (1980); Research Associate, University of Illinois (1980-82); Associate Faculty Scientist, Lawrence Berkeley National Laboratory; Member, American Chemical Society, Electrochemical Society, and Society for Electroanalytical Chemistry; Joel H. Hildebrand Chair in Chemistry (1982-1984); College of Science Alumni Achievement Award, Southern Illinois University at Carbondale (2002).