Person:

Shih, William

The creation of nanometre-sized structures that exhibit controllable motions and functions is a critical step towards building nanomachines. Recent developments in the field of DNA nanotechnology have begun to address these goals, demonstrating complex static or dynamic nanostructures made of DNA. Here we have designed and constructed a rhombus-shaped DNA origami ‘nanoactuator' that uses mechanical linkages to copy distance changes induced on one half (‘the driver') to be propagated to the other half (‘the mirror'). By combining this nanoactuator with split enhanced green fluorescent protein (eGFP), we have constructed a DNA–protein hybrid nanostructure that demonstrates tunable fluorescent behaviours via long-range allosteric regulation. In addition, the nanoactuator can be used as a sensor that responds to specific stimuli, including changes in buffer composition and the presence of restriction enzymes or specific nucleic acids.

We describe a general framework for constructing two-dimensional crystals with prescribed depth and sophisticated three-dimensional features. These crystals may serve as scaffolds for the precise spatial arrangements of functional materials for diverse applications. The crystals are self-assembled from single-stranded DNA components called DNA bricks. We demonstrate the experimental construction of DNA brick crystals that can grow to micron-size in the lateral dimensions with precisely controlled depth up to 80 nanometers. They can be designed to display user-specified sophisticated three-dimensional nanoscale features, such as continuous or discontinuous cavities and channels, and to pack DNA helices at parallel and perpendicular angles relative to the plane of the crystals.