STM spectroscopy of single DNA molecules
D. A. Ryndyk, E. Shapir, D. Porath, A. Calzolari, R. Di Felice, and G. Cuniberti
ACS Nano 3, 1651 (2009)
We briefly present the results of recent experiments of transverse STM spectroscopy of homogeneous poly(dG)-poly(dC) DNA molecules, and discuss them in the light of theoretical investigation. A semi-empirical theoretical model is adopted to describe the transverse tunneling current across a DNA molecule placed between a metallic gold substrate and a metallic STM tip. We show that the main trends in the positions and relative magnitudes of the conductance peaks can be explained by a minimal model of a double tunnel junction with the molecule-electrode couplings and the applied voltage explicitly taken into account.