Largo Julio, Starr Francis W, Sciortino Francesco
Dipartimento di Fisica and INFM-CNR-SOFT, Universita di Roma La Sapienza, Piazzale A. Moro 2, 00185 Roma, Italy.
Langmuir. 2007 May 22;23(11):5896-905. doi: 10.1021/la063036z. Epub 2007 Apr 18.
DNA is increasingly used as a specific linker to template nanostructured materials. We present a molecular dynamics simulation study of a simple DNA-dendrimer model designed to capture the basic characteristics of the biological interactions, where selectivity and strong cooperativity play an important role. Exploring a large set of densities and temperatures, we follow the progressive formation of a percolating large-scale network whose connectivity can be described by random percolation theory. We identify the relative regions of network formation and kinetic arrest versus phase separation and show that the location of the two-phase region can be interpreted in the same framework as reduced valency models. This correspondence provides guidelines for designing stable, equilibrium self-assembled low-density networks. Finally, we demonstrate a relation between bonding and dynamics, by showing that the temperature dependence of the diffusion constant is controlled by the number of fully unbonded dendrimers.