(423d) Identifying Thermally and Kinetically Favorable Conditions for DNA-Mediated Assembly of Crystal Structures

Colloidal particle self-assembly using DNA functionalized particles (DFP) has been demonstrated as a promising way to assemble nano and micro particles for various applications,like catalysis, drug delivery, and molecular sensing. Grafting DNA molecules around nanoparticles allows for the precise control of inter and intra particle interactions, and this high degree of tunability is critical to program target structures. In this research, we used molecular dynamics simulations to investigate several design parameters which affects the ability of DFPs to form crystals. Using a coarse-grained DFP model with explicit nucleotide representation that incorporates hydrogen bonding and stacking interactions, we showed that design parameters such as the DNA chain length, temperature, and pairwise interaction strength affect the ability of DFPs to form crystal structures. Those design parameters were used to create order diagrams and identified the region in the design-space where crystal formation is favored. Additionally, we studied the kinetic properties of DFPs by tracking bond survival time and diffusivity. We found that longer DNA chains slow down overall kinetics and hinder the ability of DFPs to form crystal structures. The identified region where formation of crystals is kinetically-favored is in agreement with experimental results.