  In this letter, we study the structure-transport property relationships of
small ligand intercalated DNA molecules using a multiscale modelling approach
where extensive ab-initio calculations are performed on numerous MD-simulated
configurations of dsDNA and dsDNA intercalated with two different
intercalators, ethidium and daunomycin. DNA conductance is found to increase by
one order of magnitude upon drug intercalation due to the local unwinding of
the DNA base pairs adjacent to the intercalated sites which leads to
modifications of the density-of-states in the near-Fermi energy region of the
ligand-DNA complex. Our study suggests that the intercalators can be used to
enhance/tune the DNA conductance which opens new possibilities for their
potential applications in nanoelectronics.
