Multilayered ordered arrays self-assembled from a mixed population of nanoparticles

Area of Science:

• Nanotechnology
• Materials Science
• Biophysics

Background:

• Controlling nanoparticle self-assembly is crucial for creating advanced materials.
• Virus-like particles (VLPs) and dendrimers are versatile nanoscale building blocks.

Purpose of the Study:

• To develop and apply an experimentally-informed coarse-grained model to study the self-assembly of multiple charged nanoparticles.
• To investigate the influence of ionic strength and nanoparticle charge on self-assembly.
• To explore strategies for engineering hierarchical nanostructures.

Main Methods:

• Development of a coarse-grained model for charged nanoparticle self-assembly.
• Molecular dynamics simulations of one-component and multi-component mixtures.
• Systematic variation of nanoparticle charge and solution ionic strength.
• Analysis of bound and bridging dendrimers to understand assembly mechanisms.

Main Results:

• The model accurately predicts self-assembly of single-component systems, including high-charge variants.
• P22 VLPs form ordered arrays below a threshold ionic strength dependent on variant charge.
• Gradual ionic strength reduction (dialysis) yields hierarchical multilayered core-shell structures.
• Rapid ionic strength reduction (dilution) results in amorphous aggregates with mixed compositions.

Conclusions:

• Salt dialysis is a versatile strategy for creating ordered, multilayered nanostructures from multiple nanoscale building blocks in a one-pot synthesis.
• The model provides insights into the mechanisms governing nanoparticle self-assembly and structure formation.
• Findings are consistent with experimental observations and advance the field of directed nanoparticle assembly.