Probing DNA Conductivity by Photoinduced Electron Transfer and Scanning Probe Microscopy
The fluorescent DNA probe [Ru(phen)2(dppz)]2+ is the first ruthenium complex to be shown unequivocally to intercalate DNA by insertion of the dppz ligand. It has not been possible to obtain a structure of the bound complex by NMR, so we have combined polarized spectroscopy and photophysical techniques to characterize the binding by studying interactions with several nucleic acids. The non-intercalating ligands have been varied to investigate the possibility of homo-cooperative binding; modelling indicates favourable stacking interactions between these ancillary ligands when the complexes intercalate with nearest-neighbour exclusion.
There has been considerable speculation during the past few years about the possibility that DNA can act as a wire and mediate charge transport over long distances via the p-systems of the basepair stack. The photophysics of
In complementary studies we have investigated the conductivity of single DNA molecules immobilised in a self-assembled monolayer on gold using scanning tunneling microscopy and conducting atomic force
Eimer Tuite, Per Lincoln, Björn Önfelt, Johan Olofsson, Donats Erts*, Bengt Nordén
Department of Physical Chemistry, Chalmers University of Technology,