Cooperative colloidal self-assembly of metal-protein superlattice wires

Ville Liljeström,Ville Hynninen,Jukka Hassinen,Mauri A Kostiainen,Robin H A Ras,Maria Heilala,Jussi J Joensuu,Heikki T Rekola,Päivi Törmä,Ari Ora,Olli Ikkala,Nonappa Nonappa

doi:10.1038/s41467-017-00697-z

Ville Liljeström, Ville Hynninen + Show 10 more

Open Access

https://doi.org/10.1038/s41467-017-00697-z

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Abstract

Material properties depend critically on the packing and order of constituent units throughout length scales. Beyond classically explored molecular self-assembly, structure formation in the nanoparticle and colloidal length scales have recently been actively explored for new functions. Structure of colloidal assemblies depends strongly on the assembly process, and higher structural control can be reliably achieved only if the process is deterministic. Here we show that self-assembly of cationic spherical metal nanoparticles and anionic rod-like viruses yields well-defined binary superlattice wires. The superlattice structures are explained by a cooperative assembly pathway that proceeds in a zipper-like manner after nucleation. Curiously, the formed superstructure shows right-handed helical twisting due to the right-handed structure of the virus. This leads to structure-dependent chiral plasmonic function of the material. The work highlights the importance of well-defined colloidal units when pursuing unforeseen and complex assemblies.

Highlights

Material properties depend critically on the packing and order of constituent units throughout length scales
The cooperative self-assembly is demonstrated in a colloidal system consisting of anionic tobacco mosaic virus (TMV) nanorods, which direct the assembly of cationic gold nanoparticles (AuNPs) (Fig. 1)
We have described the cooperative self-assembly mechanism that is involved in the formation of binary electrostatic self-assemblies of anionic 1D and cationic 0D colloidal particles

Summary

Introduction

Material properties depend critically on the packing and order of constituent units throughout length scales. The formed superstructure shows right-handed helical twisting due to the righthanded structure of the virus This leads to structure-dependent chiral plasmonic function of the material. In the context of supramolecular polymerization, cooperative assembly allows non-covalently connected subunits to form ordered structures instead of randomly ordered aggregates[14]. Another example shows that cooperative complexation of polyelectrolyte-surfactant systems leads to well-defined selfassembled periodicities, independent of the exact polyelectrolytesurfactant composition[15]. There are a number of sophisticated examples that show how chiral colloidal particles can be used to guide the formation of finite nanoparticle assemblies with structure dependent optical properties[19,20,21]. The combination of building units forms processable macroscopic wires with structure dependent optical properties

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