Chiral Plasmonic Crystals Self-Assembled by DNA Origami

Periodic lattices of high refractive index materials manipulate light in exceptional manners. Resulting remarkable properties range from photonic band gaps to chiral active matter, which critically depend on parameters of crystal lattices such as the unit cell, lattice type, and periodicity. In self-assembled materials, the lattice properties are inherited by the geometry and size of the macromolecules or colloidal particles assembling the unit cell. DNA origami allows for excellent control over the size and shape of assembled macromolecules while simultaneously allowing control over the interaction between them and ultimately the crystal's structure. Here, we present the assembly of chiral, rhombohedral crystals in one, two, and three dimensions built by a DNA origami tensegrity triangle. Subsequent modification of the lattice with gold nanorods converts the lattices into chiral plasmonic metamaterials active in the visible and near-infrared spectral range. We demonstrate their chiral activity and corroborate the experimental results with simulated data.