Self-assembled structures and devices

Abstract:

Practical components for three-dimensional molecular nanofabrication must be simple to produce, stereopure, rigid, and adaptable. We report a family of DNA tetrahedra, less than 10 nanometers on a side, that can self-assemble in seconds with near-quantitative yield of one diastereomer. They can be connected by programmable DNA linkers. Their triangulated architecture confers structural stability; by compressing a DNA tetrahedron with an atomic force microscope, we have measured the axial compressibility of DNA and observed the buckling of the double helix under high loads.

Abstract:

Practical components for three-dimensional molecular nanofabrication must be simple to produce, stereopure, rigid, and adaptable. We report a family of DNA tetrahedra, less than 10 nanometers on a side, that can self-assemble in seconds with near-quantitative yield of one diastereomer. They can be connected by programmable DNA linkers. Their triangulated architecture confers structural stability; by compressing a DNA tetrahedron with an atomic force microscope, we have measured the axial compressibility of DNA and observed the buckling of the double helix under high loads.

Abstract:

We report the design and fabrication of two self-assembled DNA crystals and the use of a DNA-binding protein to control the crystal structure. Both arrays are built from the same four oligonucleotides: addition of the bacterial recombination protein RuvA during self-assembly completely changes the lattice symmetry and connectivity. By analyzing transmission electron micrographs we have produced 2-D density maps of both RuvA-DNA and DNA-only crystals to below 30Å. Such specially designed 2-D DNA templates, used to create ordered protein arrays, may provide a tool for determining the structure of proteins that do not readily crystallize.© 2005 by ScienceTechnica, Inc.

Abstract:

We demonstrate the use of holographic lithography to fabricate chiral photonic crystals. These structures are calculated to exhibit strong optical activity even though they are made from material that is not intrinsically optically active. By control of the polarizations of the interfering plane waves that are used to define the three-dimensional inicrostructure it is possible to create left-and right-handed and closely related non-chiral structures. (c) 2005 Elsevier B.V. All rights reserved.

Abstract:

We demonstrate the use of rolling circle replication to template linear DNA arrays whose sizes bridge the gap between nanometre-scale self-assembly and top-down lithographic fabrication. Using rolling circle replication we have produced an oligonucleotide containing several hundred repeats of a short sequence motif. On this template we have constructed, by self-assembly, an array consisting of two parallel duplexes periodically linked by antiparallel Holliday junctions. We have observed arrays up to 10 νm in length by atomic force microscopy. © 2005 IOP Publishing Ltd.