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Sequence-Specific Electron Transfer Mediated by DNA Duplexes Attached to Gold through the Alkanethiol Linker
- Source :
- The Journal of Physical Chemistry - Part B; October 2018, Vol. 122 Issue: 44 p10077-10085, 9p
- Publication Year :
- 2018
-
Abstract
- Ability of the DNA double helix to transport electrons is its critical feature, underlying a number of important biological and biotechnological processes. Here, we show that electron transfer (ET) from the gold electrode to the DNA-bound methylene blue (MB) mediated by the DNA base-pair π-stack is less efficient in (dGdC)-rich duplexes compared to pure (dAdT) DNA. The ET rate constant ksextrapolated to the DNA surface coverage ΓDNA→ 0 is 121 ± 8 s–1for (dAdT)25, being almost twofold higher than 67 ± 3 s–1shown for (dGdC)20, consistent with the electric-field-disturbed submolecular structure of the (dGdC)20duplex earlier shown at electrified interfaces. DNA-mediated ET occurs both to MB intercalated and thus perfectly π-stacked into the (dGdC)20duplex and to MB solely groove-bound to (dAdT)25. For both (dGdC)20and (dAdT)25, ET is less efficient than ET in DNA duplexes of a mixed dA, dT, dG, dC composition. The results suggest new interpretations of the biological ET processes that may occur in dsDNA of different compositions at polarized interfaces.
Details
- Language :
- English
- ISSN :
- 15206106 and 15205207
- Volume :
- 122
- Issue :
- 44
- Database :
- Supplemental Index
- Journal :
- The Journal of Physical Chemistry - Part B
- Publication Type :
- Periodical
- Accession number :
- ejs46820202
- Full Text :
- https://doi.org/10.1021/acs.jpcb.8b07505