Patterns without patches: hierarchical self-assembly of complex structures from simple building blocks.

Michael Grünwald,Phillip L Geissler

doi:10.1021/nn500978p

Michael Grünwald, Phillip L Geissler

Open Access

https://doi.org/10.1021/nn500978p

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Abstract

Nanoparticles with “sticky patches” have long been proposed as building blocks for the self-assembly of complex structures. The synthetic realizability of such patchy particles, however, greatly lags behind predictions of patterns they could form. Using computer simulations, we show that structures of the same genre can be obtained from a solution of simple isotropic spheres, with control only over their sizes and a small number of binding affinities. In a first step, finite clusters of well-defined structure and composition emerge from natural dynamics with high yield. In effect a kind of patchy particle, these clusters can further assemble into a variety of complex superstructures, including filamentous networks, ordered sheets, and highly porous crystals.

Highlights

Living systems create and maintain their functional microscopic organization through self-assembly, the spontaneous arrangement of an initially unordered collection of biomolecular building blocks
A close look at the agents of self-assembly in living systems reveals a key aspect of the problem: Most biomolecular objects interact through directionally specific forces, so-called “patchy” interactions
Computer simulations of model nanoparticles with attractive patches have recapitulated much of the richness of nature's self-assembled structures.1À6 Synthetic nanoparticles with controlled patchiness, are largely unavailable in the laboratory, impressive progress has been made in specific cases.7À10

Summary

Introduction

Living systems create and maintain their functional microscopic organization through self-assembly, the spontaneous arrangement of an initially unordered collection of biomolecular building blocks. Because of the short-range of interactions, this modification is subtle and has little effect on assembly dynamics.] (See Methods for the specific pair potential used in our simulations.) Colloidal nanoparticles with surface-grafted DNA molecules provide one experimental realization of this system, in which the complementary sequences of DNA strands attached to monomers A and B encode the strength εAB of their attraction.11À13

Results

Conclusion