Professor Andrew Turberfield

Abstract:

We report the replication of holographically defined photonic crystals using multistage atomic layer deposition. Low- and high-temperature atomic layer depositions were combined with selective etching to deposit and remove multiple conformal thin films within three-dimensional polymer templates. Using intermediate Al 2 O 3 inverse replicas, temperature- sensitive SU-8 photonic crystal templates were faithfully replicated with TiO 2 and GaP, greatly increasing the dielectric contrasts of the photonic crystals. Optical measurements are in good agreement with the calculated band structures. © 2009 American Institute of Physics.

Abstract:

Many DNA nanostructures have been produced and a wide range of potential applications have been proposed. However, confirmation of accurate 3D construction is particularly challenging. Here, we demonstrate that cryoEM may be exploited to obtain structural information at sufficient resolution to visualize the DNA helix and reveal the absolute stereochemistry of a 7 nm self-assembled DNA tetrahedron. Structural analysis at such high resolution by cryoEM image analysis is unprecedented for any biological molecule of this size.

Abstract:

We present a facile method for linking recombinant proteins to DNA. It is based on the nickel-mediated interaction between a hexahistidine tag (His(6)-tag) and DNA functionalized with three nitrilotriacetic acid (NTA) groups. The resulting DNA-protein linkage is site-specific. It can be broken quickly and controllably by the addition of a chelating agent that binds nickel. We have used this new linker to bind proteins to a variety of DNA motifs commonly used in the fabrication of nanostructures by DNA self-assembly.