Cooperative colloidal self-assembly of metal-protein superlattice wires

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.

Phthalocyanine–Virus Nanofibers as Heterogeneous Catalysts for Continuous‐Flow Photo‐Oxidation Processes

“…Linear fitting of the squared diffraction peak indices as a function of the measured q ‐values yields a lattice constant of a = 20.1 nm (Figure c). This is in good agreement with the typical packing of highly concentrated TMV, or in presence of atomic cations or small‐size AuNPs . The observed lattice parameter is slightly higher than the TMV diameter (i.e., 18 nm), which is in close agreement with the proposed model.…”

“…Recent examples of protein crystal scaffolds with catalytic activity indicate that biohybrids can function as efficient catalysts . While protein cages such as (apo)ferritin or cowpea chlorotic mottle virus have coped the most recent developments in 3D electrostatic assemblies, other protein scaffolds such as tobacco mosaic virus (TMV) have been recently explored, yielding unidimensional morphologies …”

“…This geometry, which renders a negatively charged helix on the outer surface of the virus at pH above 4.5, can function as a well‐defined scaffold for unidimensional ensembles. TMV has been employed as drug delivery platform, as well as building block in different biohybrid arrays together with small functional molecules, or nanoparticles …”

Tobacco Mosaic Virus as a Versatile Platform for Molecular Assembly and Device Fabrication

“…TMV retains a negative surface charge above its isoelectric point near pH 3.3, so positively charged polymer precursors accumulates on the long TMV fibers that form when the pH is near 5 and can be stabilized by the surface deposition and polymerization of aniline, pyrrole, or dopamine . The hierarchical arrangement of TMV rods into larger‐scale bundles and lattices has also been accomplished using metal nanoparticles, organometallic compounds, and polysaccharides . Distinct from variations on the typical rod‐like form of TMV, spherical nanoparticles from TMV CP have been made by altering CP interactions through simple thermal treatments and through chemical modification …”

Highly ordered protein cage assemblies: A toolkit for new materials

“…(e) Optical disassembly of magnetoferritin complexes. Schematic (top) and transmission electron microscope (TEM) images (bottom) of free magnetoferritin self‐assembly with cationic dendrons and disassembly back to nanoparticles (NPs) after exposure to ultraviolet (UV) radiation (Reprinted with permission from Liljeström et al (). Copyright 2017 Nature, Korpi et al ().…”