DNA nanopositioning and alignment by electron-beam-induced surface chemical patterning.

Abstract

Nanopositioning and alignment of arrays of DNA molecules on a surface by combination of high-resolution prepatterning and standard macroscopic deposition is presented. Direct electron beam exposure of a graphite substrate activated by amino groups neutralizes locally the surface charge, preventing the DNA adhesion during the consequent deposition. Because of the high resolution of the electron beam writing process, precise active patches can be created directly on the functionalized surface. Narrow (50 nm) stripe patterns produce both positioning and alignment acting as electrostatic traps for the DNA molecules. The approach is demonstrated using triple- and double-stranded DNA of medium length (350 nm). High yield of alignment and regular arrangement of the deposited molecules are achieved in a simple way within large areas.