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Updated: Nov 24, 2025
Stable DNA Motifs, 1D and 2D Nanostructures Constructed from Small Circular DNA Molecules
Published on: April 12, 2019
Probing the Consequences of Cubic Particle Shape and Applied Field on Colloidal Crystal Engineering with DNA
Zachary J Urbach1, Sarah S Park1, Steven L Weigand2
1Department of Chemistry, International Institute for Nanotechnology, Northwestern University, Evanston, IL, 60208, USA.
Abstract:
In a magnetic field, cubic Fe3 O4 nanoparticles exhibit assembly behavior that is a consequence of a competition between magnetic dipole-dipole and ligand interactions. In most cases, the interactions between short hydrophobic ligands dominate and dictate assembly outcome. To better tune the face-to-face interactions, cubic Fe3 O4 nanoparticles were functionalized with DNA. Their assembly behaviors were investigated both with and without an applied magnetic field. Upon application of a field, the tilted orientation of cubes, enabled by the flexible DNA ligand shell, led to an unexpected crystallographic alignment of the entire superlattice, as opposed to just the individual particles, along the field direction as revealed by small and wide-angle X-ray scattering. This observation is dependent upon DNA length and sequence and cube dimensions. Taken together, these studies show how combining physical and chemical control can expand the possibilities of crystal engineering with DNA.
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