Esther M. Conwell

Esther M. Conwell

Research Professor

Ph.D. 1948, University of Chicago

Electrical and Optical Properties of Organic Semiconductors

Professor Conwell and her group have been studying transport of excess electrons and holes along the base stack in DNA. Transport of charges in DNA is important because (1) It could lead to mutations and carcinogenesis and (2) If the transport is good, DNA could play a useful role as electrical wires in very tiny circuits (nanocircuits) which it can also help to assemble. Measurements of conduction in DNA have led to controversial results, some characterizing it as an insulator, some as a metal, and still others as a semiconductor. Professor Conwell believes the weight of evidence favors the latter. Because DNA is surrounded by water and ions, a charge added to a DNA molecule gives rise to a strong polarization, which lowers its energy. The charge and the polarization move together as a kind of particle, a polaron. Professor Conwell and her group have been calculating the properties of these polarons and how they contribute to conduction in DNA. They have shown that the existence of polarons can explain a number of different experimental results that have been obtained for DNA, and have predicted how fast the polarons can move at low temperatures in an electric field or on a DNA with a difference in oxidation potentials due to donor and acceptor molecules at the respective ends. It is known that at temperatures as high as room temperature the bases in DNA undergo strong thermal fluctuations. We are now investigating how these strong fluctuations affect the motion of the polarons.

Selected Publications

Kravec, S. M., Kinz-Thompson, C. D., Conwell, E. M.  "Localization of a Hole on an Adenine-Thymine Radical Cation in B-Form DNA in Water,"  J. Phys. Chem.  20111156166-6171.
Kucherov, V. M., Kinz-Thompson, C. D., Conwell, E. M.  "Polarons in DNA Oligomers,"  J. Phys. Chem. C.  20101141663.
Kinz-Thompson, C. D., Conwell, E. M.  "Proton Transfer in Adenine-Thymine Radical Cation Embedded in B-form DNA,"  J. Phys. Chem. Lett.  201011403.
Elias, B., Shao, F., Barton, J. K., Conwell, E. M.  "Charge Migration along the DNA Duplex: Hole vs. Electron Transport,"  J. Am. Chem. Soc.  20081301152.
Conwell, E. M.  "Effect of Negative Differential Conductance in Carbon Nanotubes,"  NanoLett  200881253-1256.
Conwell, E. M., McLaughlin, P. M., Bloch, S. M.  "Charge Transfer Excitons in DNA,"  J. Phys. Chem. B  200812122268-2272.
Conwell, E. M., Bloch, S. M., McLaughlin, P. M., Basko, D. M.  "Duplex Polarons in DNA,"  J. Am. Chem. Soc.  20071299175-9181.
Conwell, E. M., Basko, D. M.  "Effect of Water Drag on Diffusion of Drifting Polarons in DNA,"  J. Phys. Chem. B  200611023603-23606.
Conwell, E. M., Bloch, S. M.  "Base Sequence Effects on Transport in DNA,"  J. Phys. Chem. B  20061105801-5806.
Conwell, E. M., Park, J. H., Choi, H. Y.  "Polarons in DNA: Transition from Guanine to Adenine Transport,"  J. Phys. Chem. B  20051099760-9763.
Conwell, E. M.  "Charge Transport in DNA in solution: The Role of Polarons,"  Proc. Natl. Acad. Sci. U.S.A.  20051028795-8799.
Basko, D. M., Conwell, E. M.  "Transport and Optical Properties of DNA, in Organic Nanophotonics,"  Kliewer Academic Publishers, Netherlands  2003pp. 193-206.
Conwell, E. M., Basko, D. M.  "Polarons and Conduction in DNA,"  Synth. Met.  20031371381-1383.
Basko, D. M., Conwell, E. M.  "Effect on Solvation on Hole Motion in DNA,"  Phys. Rev. Let.  200288098102.
Conwell, E. M., Basko, D. M.  "Hole Traps in DNA.,"  J. Am. Chem. Soc.  200112311441-11445.
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Professor Conwell's Contact Information...

Office: Hutchison 415
Phone: (585) 275-5841