(728d) The Role of Interaction Heterogeneity in the Self-Assembly of DNA-Functionalized Colloids
The multivalent nature of DNA-mediated particle binding introduces constraints for assembly by increasing the temperature dependence of the resultant interparticle potential and consequently narrowing the operating window for high quality crystallization. For a given areal density of DNA strands, this effect becomes more pronounced for larger particles and represents a key challenge for DNA-driven colloidal assembly
The beneficial impact of interaction heterogeneity is shown to arise from a synergistic combination of two effects. First, we employ umbrella sampling simulations to show that heterogeneity strongly lowers the free energy barrier associated with the nucleation of crystals by the formation of strongly-bound small clusters. Concurrently, non-equilibrium growth simulations show that variations in the interaction strength between particles inhibit gelation and polycrystallinity by keeping the number of such nuclei low, allowing individual nuclei to grow unhindered.