Ab initio study of DNA nucleotides sandwiched between Au(111) electrodes

Abstract

Using first-principles calculations, we study the electronic properties of the four DNA nucleotides sandwiched between two Au(111) electrodes. The geometrical structure of the systems is a realistic model of the recently proposed devices for DNA sequencing. For these metal-molecule-metal systems, we calculate the total and local density of states (DOS, LDOS), and the metal-molecule charge transfers. Our results suggest that the qualitative differences between the four systems are sufficient to ensure the recognition of the DNA bases by the proposed device. Nevertheless, the full investigation of the quantitative features of the current-voltage curves is needed to decide if the practical use is possible. © 2009 IOP Publishing Ltd.