Nano-Structured Beta-Gallia-Rutile Surfaces as Substrates for DNA Self-Assembly

Abstract

AbstractA nano-structured beta-gallia-rutile (BGR) substrate capable of binding DNA was synthesized. Beta-gallia groups diffuse into [001] single crystal rutile along {210}rplanes, generating hexagonally shaped tunnel sites between the beta-gallia subunits (repeating ∼1 nm). The tunnel sites, approximately 2.5 Å in diameter, are preferred regions for cation incorporation. Divalent cations have been used previously to adsorb DNA to mica surfaces. For the BGR system, the site selectivity of the cations for tunnel sites could lead to controllable / tailor-able DNA adsorption. DNA buffers containing Cu (II), Fe (II), and Ni (II) cations were deposited on BGR substrates. The DNA adsorption was investigated with tapping mode atomic force microscopy (AFM) to determine the suitability of using BGR substrates as a means to self assemble DNA constructs for nano-electronic applications. At the concentrations tested, only solutions containing Ni (II) ions were capable of binding DNA sufficiently for AFM imaging; there was no evidence of site specific attachment.