Programming Defects and Cavities into Colloidal Crystals Engineered With DNA

Taking inspiration from seed-mediated crystal growth in atomic and molecular systems, a strategy is developed for incorporating particle and volume defects into the interior of colloidal crystals consisting of programmable atom equivalents (PAEs, oligonucleotide-functionalized nanoparticles) assembled with DNA. Discrete PAEs spanning a range of shapes, sizes, and compositions serve as nucleation sites for seed-mediated colloidal crystal growth and are incorporated into the centers of colloidal crystal lattices as cavities. Importantly, seed PAE shapes or sizes that are geometrically mismatched with the colloidal crystal lattice symmetry introduce defects such as local lattice disorder and long-range grain boundaries that arise through geometric frustration. Colloidal crystals synthesized with plasmonic seed particles exhibit near-infrared (NIR) wavelength scattering cross-sections that are highly dependent upon cavity/particle size and shape. Taken together, these findings establish a platform for the deliberate introduction of 2 and 3D defects into colloidal crystals, which may inform the design of structures and materials for thermal management, sensing, and catalysis.