Electronic properties of guanine-based nanowires

We present a first-principles study of the electronic and conduction properties of a few classes of nanowires composed of guanine (G) molecules, self-assembled in different geometries. We first analyze the effect of the vertical pi-pi interaction in model G-stack columns. Then, we exploit the results obtained from those models to interpret the features of realistically stacked and hydrogen-bonded aggregates, namely the guanine quadruple helices and the planar ribbons. With respect to natural DNA, the different structures drastically affect the bonding pattern among the bases, introducing novel features in the electronic properties of the systems. These supramolecular G-aggregates, alternative to DNA, are expected to show interesting properties for molecular electronics applications.