Nucleic acid nanotechnology

Abstract:

Metastable two-stranded DNA loops can be assembled into extended DNA oligomers by kinetically controlled self-assembly. Along the designed reaction pathway, the sequence of hybridization reactions is controlled by progressively revealing toeholds required to initiate strand-displacement reactions. The product length depends inversely on seed concentration and ranges from a few hundred to several thousand base-pairs.

Abstract:

The second law of thermodynamics requires that directed motion be accompanied by dissipation of energy. Here we demonstrate the working principles of a bipedal molecular motor. The motor is constructed from DNA and is driven by the hybridization of a DNA fuel. We show how the catalytic activities of the feet can be coordinated to create a Brownian ratchet that is in principle capable of directional and processive movement along a track. This system can be driven away from equilibrium, demonstrating the potential of the motor to do work.

Abstract:

We have registered the position and wavelength of a single InGaAs quantum dot using an innovative cryogenic laser lithography technique. This approach provides accurate marking of the location of self-organized dots and is particularly important for realizing any solid-state cavity quantum electrodynamics scheme where the overlap of the spectral and spatial characteristics of an emitter and a cavity is essential. We demonstrate progress in two key areas towards efficient single quantum dot photonic device implementation. Firstly, we show the registration and reacquisition of a single quantum dot with 50 and 150 nm accuracy, respectively. Secondly, we present data on the successful fabrication of a photonic crystal L3 cavity following the registration process.