Self-assembly dynamics of reconfigurable colloidal molecules

TL;DR

This paper presents a method to create reconfigurable colloidal molecules with flexible bonds using mobile DNA linkers, enabling the study and application of complex self-assembled structures.

Contribution

It introduces a novel approach to assemble reconfigurable colloidal molecules with controlled valence and flexibility using mobile DNA linkers, advancing the modeling of molecular behavior.

Findings

Successful assembly of reconfigurable colloidal clusters

Control over cluster size and valence via particle ratios

Quantitative analysis of self-assembly dynamics

Abstract

Colloidal molecules are designed to mimic their molecular analogues through their anisotropic shape and interactions. However, current experimental realizations are missing the structural flexibility present in real molecules thereby restricting their use as model systems. We overcome this limitation by assembling reconfigurable colloidal molecules from silica particles functionalized with mobile DNA linkers in high yields. We achieve this by steering the self-assembly pathway towards the formation of finite-sized clusters by employing high number ratios of particles functionalized with complementary DNA strands. The size ratio of the two species of particles provides control over the overall cluster size, or, "valence", as well as the degree of reconfigurability. The bond flexibility provided by the mobile linkers allows the successful assembly of colloidal clusters with the geometrically expected maximum valence. We quantitatively examine the self-assembly dynamics of these flexible colloidal molecules by a combination of experiments, molecular dynamics simulations, and an analytical model. Our "flexible colloidal molecules" are exciting building blocks for investigating and exploiting the self-assembly of complex hierarchical structures, photonic crystals and colloidal meta-materials.