Assembly of nanoparticle patterns with single-particle resolution using DNA-mediated charge trapping technique: Method and applications

We report a unique approach for producing one-dimensional gold-nanoparticle patterns with single-particle resolution in which the linewidth is only limited by the particle size. In this approach, a focused electron beam was first utilized to generate a positive charge layer on a SiO2 surface. Biotinated DNA molecules attracted by these positive charges were subsequently used to grasp Au-nanoparticles revealing the e-beam exposure patterns. Due to repulsive force between An colloidal particles, the particles in the single-line patterns were orderly separated. We further show that the single-line patterns hold potential in nano-photonics and nano-electronics. For the latter, we demonstrate that the line patterns can serve as a template for conductive nanowires of high or low resistance. While low resistance wires showed linear current-voltage characteristics with an extremely high maximum allowed current density, the high resistance wires exhibited charging effect with clear Coulomb oscillation behavior at low temperatures. This demonstrates that the technique is capable of producing interconnects as well as single-electron-transistors, and opens up possibilities for fabrication of integrated circuits.