Professor, Chemistry

Department of Chemistry
University of Cincinnati
120 Crosley
P.O. Box 210172
Cincinnati, OH 45221-0172

Telephone: (513) 556-9210
Fax: (513) 556-9239

Education:
PhD, University of North Carolina at Chapel Hill, 1968

Research: Analytical Chemistry

• Spectroelectrochemistry
• Chemical sensors & biosensors
• Polymer modified electrodes
• Electrochemical immunoassay
• Microfluidic systems for chemical analysis

My research interests are primarily in sensors, electroanalytical chemistry, and bioanalytical chemistry. Many of the projects are interdisciplinary and involve collaborations with other groups in chemistry, engineering, medical sciences, industry, government labs, and other universities.

Novel spectroelectrochemical sensor. A novel sensor with remarkable selectivity has been developed by combining partitioning into a film, electrochemistry, and spectroscopy in a single device. The sensor is based on multiple internal reflection at an optically transparent electrode (OTE). The OTE is coated with a thin chemically-selective film that serves to enhance detection limit by preconcentrating the analyte. The evanescent field at the points of internal reflection penetrates the film so that electrochemistry within the film can be monitored optically. Project areas include new selective films, strategies for detecting analytes with poor optical properties, instrumentation, theory, and applications such as sensors for nuclear waste and polycyclic aromatic hydrocarbons in the environment.

Biosensors. Biosensors use selective biological recognition reactions to target a specific analyte. We have made significant contributions to the development of electrochemical immunosensors where the biological recognition element is an antibody. Projects include immunoassay based on capture antibody immobilized on paramagnetic microbeads, immunoassay on a microfabricated chip (i.e., a laboratory on a chip), and electrochemical detection with interdigitated array microelectrodes and carbon nanotubes. Application areas include detection of herbicides, pesticides, toxins, viruses and bacteria in water; the analysis of samples of medical importance such as from neonates and the elderly where sample size is limited; and forensic analysis where the amount of sample available for analysis can also be extremely small.

Capillary electrophoresis on a microchip. A goal of this research is to significantly improve the determination of trace amounts of biologicals with respect to speed of analysis, selectivity, and limit of detection, versus the standard methodology. Aptamer-based assays of polypeptides and proteins are used as illustrative chemical systems. Affinity capillary electrophoresis on a multilane plastic microchip with detection by laser induced fluorescence is the analytical technique.

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