Session:

DNA-guided nanoparticle self-assembly has emerged as a promising method to form designable and ordered 3D nanomaterials. However, the isotropic nature of interactions of spherical nanoparticle makes it difficult to form designed structures. In contrast, DNA origami polyhedron frames loaded with nanoparticles can be assembled to form diverse crystal symmetries through the use of directional bonds. Specifically, the directionality of interactions is provided through origami shape and placement of addressable bonds, while the specific DNA sequences prescribe interaction addressability. Recently, an inverse design approach has been developed by our group to form a variety of arbitrary crystal structures from octahedral origami by using different addressable bonds to promote a desired crystal symmetry. However, the assembly pathway plays an important role in structure formation. We investigated how the self-assembly pathway can be controlled through modulating the relative binding energies of DNA mediated interactions. In this work, the assembly of DNA origami octahedral frames with two unique interaction types with varied relative binding energies was studied. Through a combination of small angle x-ray scattering (SAXS) and scanning electron microscopy, we demonstrate that while the local crystal structure is preserved, the long-range crystal order and morphology of the assembled crystal is strongly affected by the relative binding energies and coordination of addressable DNA interactions. We further apply these findings to tune the assembly pathway and promote the formation of a desired crystal structure and morphology.

Co-Author(s): Jason Kahn (Brookhaven National Laboratory), Brian Minevich (Columbia University), Aaron Michelson (Brookhaven National Laboratory), Oleg Gang (Columbia University)

Daniel Redeker

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