Poster abstracts

Poster number 111 submitted by Joshua Johnson

Control of DNA Origami Mechanisms via Gold Nanoparticles

Joshua Johnson (Biophysics), Abhilasha Dehankar (Chemical and Biomolecular Engineering), Carlos Castro (Mechanical and Aerospace Engineering, Biophysics), Jessica Winter (Chemical and Biomolecular Engineering, Biomedical Engineering)

Abstract:
A major direction of research in DNA origami is the folding of DNA into complex 3D shapes with the inclusion of flexible regions to form dynamic nanomachines that approximate macroscale machine elements[1]. DNA origami has previously been used in combination with other nanomaterials such as gold nanoparticles there has yet to be a demonstration of nanoparticles used for the precise control of nanostructure actuation[2, 3]. Using a DNA origami hinge mechanism we have included single-stranded overhangs which bind the top and bottom beam to a DNA-conjugated gold nanoparticle. By varying the distance from the hinge vertex and the nanoparticle size we have shown that the angular distributions of the hinge are highly tunable. Changing the affinity of binding of the bottom beam relative to the top beam allows for actuation of the hinge via DNA melting without needing to release the nanoparticle entirely. Transitions between an open and closed hinge configuration are reversible compared to hinges closed via geometrically equivalent DNA linkers. We hypothesize that the high polyvalency of well coated nanoparticles offers enhanced actuation for this particular actuation scheme. Fluorescence measurements monitoring opening and closing kinetics of constructs show that actuation is limited by heat diffusion into the sample volume. Preliminary results indicate that locally heating nanoparticles via laser excitation is sufficient to open hinges. This demonstrates a novel method of optomechanical transduction and can be used for rapid nanoscale manipulation.

References:
[1] A. E. Marras, L. Zhou, H. J. Su, and C. E. Castro, "Programmable motion of DNA origami mechanisms," Proc Natl Acad Sci U S A, vol. 112, pp. 713-8, Jan 20 2015.
[2] A. Kuzyk, R. Schreiber, H. Zhang, A. O. Govorov, T. Liedl, and N. Liu, "Reconfigurable 3D plasmonic metamolecules," Nature materials, vol. 13, pp. 862-866, 2014.
[3] R. Schreiber, N. Luong, Z. Fan, A. Kuzyk, P. C. Nickels, T. Zhang, et al., "Chiral plasmonic DNA nanostructures with switchable circular dichroism," Nature communications, vol. 4, 2013.

Keywords: DNA origami, nanoparticles, nanomachines