Electronic energy delocalization and dissipation in single- and double-stranded DNA
-
Edited by Esther M. Conwell, University of Rochester, Rochester, NY, and approved January 17, 2007 (received for review August 4, 2006)
Abstract
The mechanism that nature applies to dissipate excess energy from solar UV light absorption in DNA is fundamental, because its efficiency determines the vulnerability of all genetic material to photodamage and subsequent mutations. Using femtosecond time-resolved broadband spectroscopy, we have traced the electronic excitation in both time and space along the base stack in a series of single-stranded and double-stranded DNA oligonucleotides. The obtained results demonstrate not only the presence of delocalized electronic domains (excitons) as a result of UV light absorption, but also reveal the spatial extent of the excitons.
Footnotes
- *To whom correspondence should be addressed. E-mail: fiebig{at}bc.edu
-
Author contributions: T.F. designed research; I.B., Q.W., M.R., and A.T. performed research; I.B., M.R., A.T., and T.F. analyzed data; and T.F. wrote the paper.
-
The authors declare no conflict of interest.
-
This article is a PNAS direct submission.
-
↵ † A similar analysis to determine the exciton delocalization length in bacterial light-harvesting antenna systems was applied in ref. 37.
- Abbreviations:
- dA,
- deoxyadenosine;
- ESA,
- excited-state absorption;
- IC,
- internal conversion.
- © 2007 by The National Academy of Sciences of the USA
