%0 Journal Article
%T Directional Preference of DNA-Mediated Electron Transfer in Gold-Tethered DNA Duplexes: Is DNA a Molecular Rectifier?
%A Kékedy-Nagy L
%A Ferapontova EE
%J Angew Chem Int Ed Engl
%V 58
%N 10
%D 03 2019 4
%M 30428159
%F 16.823
%R 10.1002/anie.201809559
%X Electrical properties of self-assembling DNA nanostructures underlie the paradigm of nanoscale bioelectronics, and as such require clear understanding. DNA-mediated electron transfer (ET) from a gold electrode to DNA-bound Methylene Blue (MB) shows directional preference, and it is sequence-specific. During the electrocatalytic reduction of [Fe(CN)6 ]3- catalyzed by DNA-bound MB, the ET rate constant for DNA-mediated reduction of MB reaches (1.32±0.2)103 and (7.09±0.4)103  s-1 for (dGdC)20 and (dAdT)25 duplexes. The backward oxidation process is less efficient, making the DNA duplex a molecular rectifier. Lower rates of ET via (dGdC)20 agree well with its disturbed π-stacked sub-molecular structure. Such direction- and sequence-specific ET may be implicated in DNA oxidative damage and repair, and be relevant to other polarized surfaces, such as cell membranes and biomolecular interfaces.