Multilayered ordered arrays self-assembled from nanoparticle mixtures via salt dialysis

Biology has inspired many bottom-up strategies for synthesizing materials via the self-assembly of nanostructures for applications in drug delivery, catalysis, and sensing, among others. Using coarse-grained molecular dynamics simulations and experiments, we study the self-assembly of mixtures of up to 4 different types of virus-like particles (VLPs) derived from bacteriophage P22, which can be genetically engineered to express different surface charges, over a broad range of salt concentration (~0.01 - 1 M). Through different combinations of two- , three-, and four-component mixtures of VLPs, we demonstrate that salt dialysis can be used as an approach to engineer multilayered ordered arrays in the presence of oppositely-charged linker macromolecules, where each layer is composed of a single type of VLP. VLP-VLP pair correlation functions are extracted to characterize the structure of the core-shell ordered arrays, emphasizing the differences between the aggregates resulting from rapid quenching versus dialysis of the VLP solutions. In solutions with multiple VLP types, we observe that the presence of higher charged variants increases the ionic strength threshold of the smaller charged variant to assemble into ordered structures. Linker-VLP correlation functions are extracted to explain this effect.