A method for laying out arrays of components in programmable 2D arrangements with nanometer-scale precision is needed for the manufacture of high density nanoelectronic circuitry. We report programmed self-assembly of gold prototype nanoelectronic components into closely packed rows with precisely defined inter-row spacings by in situ hybridization of DNA-functionalized components to a preassembled 2D DNA scaffolding on a surface. This approach is broadly applicable to the manufacture of nanoscale integrated circuits for logic, memory, sensing, and other applications.

The bottom-up spatial organization of potential nanoelectronic components is a key intermediate step in the development of molecular electronics. We describe robust 3-space-spanning DNA motifs that are used to organize nanoparticles in 2D. One strand of the motif ends in a gold nanoparticle; only one DNA strand is attached to the particle. By using two of the directions of the motif to produce a two dimensional crystalline array, one direction is free to bind gold nanoparticles. Identical motifs, tailed in different sticky ends enable the 2D periodic ordering of 5 nm and 10 nm diameter gold nanoparticles. KeywordsDNA self-assembly; 2D DNA arrays; Organizing Matter with DNA; Atomic Force Microscopy; Metallic Nanoparticles; Robust DNA Motifs Metallic and semiconductor nanoparticles exhibit quantized optical and electronic properties that might be exploited in the design of future nanoelectronic devices. 1-3 However, this application requires the deliberate and precise organization of nanoparticles into specific designed structural arrangements. The control of the structure of matter on the finest possible scale entails the successful design of both stiff intramolecular motifs and robust intermolecular interactions. The specificity of DNA base-pairing has provided a 'smart-glue' approach to programming interactions between particles via hybridization of specifically designed linker strands. 4,5 Previously, stiff motifs 6 based on branched DNA have been used to produce DNA structures with a variety of patterns that are visible in the AFM; these include stripes from double crossover (DX) molecules, 7 arrays with tunable cavities from DNA parallelograms, 8 and honeycombs from DX triangles. 9 DNA-functionalized 1.4 nm gold nanoparticles have been assembled into linear arrays forming parallel stripes on a 2D DNA striped scaffolding by self-assembly during scaffolding formation 10 and 6 nm gold nanoparticles with multiple DNA attachments have been fashioned into similar arrays by in situ hybridization to a pre-assembled scaffolding on a striped DX surface. 11 Sequenceencoded in situ assembly of 5 nm and 10 nm gold particles in alternating stripes has also been achieved. 12 While such linear nanoparticle arrays are of interest for some applications, * Address correspondence to this author at ned.seeman@nyu.edu. Supporting Information Available:The sequences of the molecules used and experimental methods. This material is available free of charge via the Internet at http://pubs.acs.org/. Our experience with honeycomb lattices demonstrates that cohesion by two sticky ends on each end of a DX molecule is more robust than a single sticky end; we were unable to obtain the honeycomb arrays if only a single sticky end was used. 9 We have built several motifs that span 3-space (e.g., 6-helix bundles 15 ); one of these motifs (termed a 3D-DX triangle) is based on Mao et al.'s tensegrity triangle, 16 but contains DX molecules, instead of single helices in each of its three domains (Fig. 1). It is possible to produce 2D lat...