Controlling Lattice Organization, Assembly Pathways and Defects in Self-Assembled DNA-Based Nanomaterials

In our recent work, we have devised methods to separate the shape/interactions of a nanoparticle (NP) and the fully organized crystal into which it assembles into. This goal was achieved by encapsulating the NP into a DNA frame so that the NP is simply cargo whose assembly is templated by the structure that the DNA frame follows; the frame’s shape and bonding architecture thus controls the crystal morphology that results. While this concept is facile for ordering NPs into arbitrarily desired crystal structures, the presence of defects limits the size and the perfection of the crystals that result. What controls defect formation and how we can manipulate, control and minimize defects so that we can macroscopically large NP crystals then represents the focus of the project. To this end, in this work we use a tight combination of experiments and mean-field liquid-state theory & molecular simulations to develop robust and tailorable strategies for the assembly of desired NP lattice types using directional and highly-specific bonds of DNA frame constructs. In addition, using a suit of advanced characterization and computational methods we aim to delineate the pathways for frame crystallization and from there the propensity to create and therefore minimize defects. In parallel, we shall develop novel 3D electron and x-ray-based imaging techniques and analysis methods that will allow us to measure and quantify defect structures.