Prescribed nanoparticle cluster architectures and low-dimensional arrays built using octahedral DNA origami frames

Abstract

Reliably creating three-dimensional (3D) mesoscale clusters, in which nanoparticles are spatially arranged in pre-determined positions, is the first step towards arbitrarily designed self-assembled architectures. These engineered clusters would be the mesoscale analogs of molecules and would thus offer tailored nanoparticles properties due to the collective effects. However, establishing a flexible and broadly applicable platform for the fabrication of nanoparticles architectures, as well as probing their 3D non-periodic organizations, is challenging. Here we report a novel strategy for assembling 3D nanoparticle clusters: designing a molecular frame with encoded vertices for particles placement. By positioned specific particles types at the vertices of such frame, a DNA origami octahedron, we fabricated clusters of various symmetries and particles composition. We applied the Cryo-EM methods to uncover the DNA frame structure, and to reveal that nanoparticles are spatially coordinated in the prescribed manner. Employing the demonstrated assembly strategy, we have created nanoclusters with different chiroptical activities based on the specifically encoded center-symmetrical DNA frame and the same set of nanoparticles. We also show that octahedra with particularly selected vertices can serve as tailorable interparticle linker with a certain geometry of interparticle connections, thus, allowing for assembly of 1D or 2D arrays with designed particle arrangements.