posted on 2013-06-12, 00:00authored byTing I.
N. G. Li, Rastko Sknepnek, Monica Olvera de la Cruz
The
selectivity of DNA recognition inspires an elegant protocol
for designing versatile nanoparticle (NP) assemblies. We use molecular
dynamics simulations to analyze dynamic aspects of the assembly process
and identify ingredients that are key to a successful assembly of
NP superlattices through DNA hybridization. A scale-accurate coarse-grained
model faithfully captures the relevant contributions to the kinetics
of the DNA hybridization process and is able to recover all experimentally
reported to date binary superlattices (BCC, CsCl, AlB2,
Cr3Si, and Cs6C60). We study the
assembly mechanism in systems with up to 106 degrees of
freedom and find that the crystallization process is accompanied with
a slight decrease of enthalpy. Furthermore, we find that the optimal
range of the DNA linker interaction strengths for a successful assembly
is 12–16kBT, and
the optimal mean lifetime of a DNA hybridization event is 10–4–10–3 of the total time it takes to form
a crystal. We also obtain the optimal percentage of hybridized DNA
pairs for different binary systems. On the basis of these results,
we propose suitable linker sequences for future nanomaterials design.