Research Interests
Biosensors are analytical devices that can utilize a biological molecule (i.e., enzyme, antibody, or receptor) as a sensing element to impart specificity to an electrochemical, optical, or acoustic transducer. The transducer converts the biochemical response into a measurable electrical signal thereby allowing information about the analyte of interest to be obtained. The long-term goal of my research is to develop potentially specific and sensitive biosensors for application in the areas of drug metabolism and drug design. My research interests and experience are in the areas of metalloenzymes, biological electron transfer, and chemically modified electrodes. This research focuses on the construction of biologically modified electrode surfaces for both fundamental and applied studies. Two areas of biosensor research are highlighted here: the immobilization of enzymes in electrode-supported lipid bilayer membranes as well as the immobilization of other biologically relevant species (i.e., DNA and proteins) for sensing applications.
Electrode-Supported Lipid Bilayer Membranes
We are interested in using standard electrochemical techniques to study membrane resident electron transfer enzymes. Self-assembly chemistry and deoxycholate dialysis are used to deposit lipid bilayer membranes containing enzymes on metal electrode surfaces for the detection of clinically relevant substrates. Enzymes of interest include cytochrome c oxidase, monoamine oxidases, and drug metabolizing cytochrome P450.
Binding of Platinum-based Anticancer Drugs to DNA
The aim of this research is to probe, in real time, binding of platinum-based anticancer drugs to specific sequences of DNA/RNA to evaluate the contributions of both electrostatic and hydrogen bonding interactions. The binding rates are being studied using a quartz crystal microbalance (QCM) electrode that has been modified with a target DNA/RNA sequence. This approach is also well-suited for evaluating the recognition of DNA-platinum adducts by biomolecules possibly involved in repair of damaged DNA and drug resistance.
Selected Publications
Burgess, J. D.; Rhoten, M. C.; Hawkridge, F. M. “Cytochrome c Oxidase Immobilized in Stable Supported Lipid Bilayer Membranes” Langmuir 1998, 14, 2467-2475.
Burgess, J. D.; Rhoten, M. C.; Hawkridge, F. M. “Interconversion Between Resting and Pulsed Cytochrome c Oxidase in Electrode-Supported Lipid Bilayer Membranes” J. Am. Chem. Soc. 1998, 120, 4488-4491.
Burgess, J. D.; Jones, V. W.; Porter, M. D.; Rhoten, M. C.; Hawkridge, F. M. “Scanning Force Microscopy Images of Cytochrome c Oxidase Immobilized in an Electrode-Supported Lipid Bilayer Membrane” Langmuir, 1998, 14, 6628-6631.
Rhoten, M. C.; Burgess, J. D.; Hawkridge, F. M. “Temperature and pH Effects on Cytochrome c Oxidase in an Electrode-Supported Lipid Bilayer Membrane” Electrochim. Acta, 2000, 45, 2855-2860.
Rhoten, M. C.; Burgess, J. D.; Hawkridge, F. M. “The Reaction of Cytochrome c from Different Species with Cytochrome c Oxidase Immobilized in an Electrode Supported Lipid Bilayer Membrane” J. Electroanal. Chem., 2002, 534, 143-150.
Su, L.; Kelly, J.; Hawkridge, F. M.; Rhoten, M. C.; "Electroreduction of Oxygen by Cytochrome c Oxidase Immobilized in Electrode-Supported Lipid Bilayer Membranes" Chemistry & Biodiversity, 2004, 1, 1281-1288.
Lewis, K. L.; Hawkridge, F. M.; Ward, K.; Rhoten, M. C. "Immobilization of Cytochrome c Oxidase into Electrode-Supported Lipid Bilayer Membranes for in vitro Cytochrome c Sensing", IEEE Sensors J., 2004, in press.
Su, L.; Kelly, J.; Hawkridge, F. M.; Rhoten, M. C.; "Characterization of Cyanide Binding to Cytochrome c Oxidase Immobilized in an Electrode-Supported Lipid Bilayer Membrane" J. Electroanal. Chem., 2004, in press.
Su, L.; Hawkridge, F. M.; Rhoten, M. C.; "A Comparison of Monomer and Dimer Cytochrome c Oxidase Immobilized in Electrode-Supported Lipid Bilayer Membranes" 2004, in preparation.