(749b) Material Design By DNA-Mediated Interactions between Colloids

The ability to rationally design and synthesize complex nano-, micro-, and hierarchically structured materials with tunable functionality represents a holy grail that holds exciting promise for revolutionizing materials applications spanning catalysis, molecular sensing, drug delivery, molecular and charge manipulation, and beyond. Such applications hinge upon precise control over morphology, topology, material connectivity, and function, and demand accommodation of a wide range of materials compositions spanning organic, inorganic, and hybrid structures. One of the most promising approach to achieve such unprecedented control over colloidal self-assembly is to use DNA-mediated interactions between particles functionalized with partially complementary DNA sequences. In general, DNA functionalized particles have several adjustable parameters: the hybridization interaction strength, temperature, solution stoichiometry and DNA grafting density. Using molecular dynamics simulations of a coarse-grained model developed specifically to study such systems, we show that variations in these key factors provide selectivity between different lattice structures such as body-centered cubic (BCC) and close-packed (FCC and HCP) structures. In addition, we are able to program structures that interconvert via diffusionless transformations via external stimuli such as temperature changes.