Light-Driven Aqueous Dissipative Pseudorotaxanes with Tunable Fluorescence Enabling Deformable Nano-Assemblies

Developing an artificial dynamic nanoscale molec-ular machine that dissipatively self-assembles far from equilibrium is fundamentally important but is significantly challenging. Herein, we report dissipatively self-assembling light-activated convertible pseudorotaxanes (PRs) that show tunable fluorescence and enable deformable nano-assemblies. A pyridinium-conjugated sulfonato-merocyanine derivative (EPMEH) and cucurbit[8]uril (CB[8]) form the 2EPMEH subset of CB[8] [3]PR in a 2:1 stoichiometry, which phototransforms into a transient spiropyran containing 1:1 EPSP subset of CB[8] [2]PR when exposed to light. The transient [2]PR thermally relaxes (reversibly) to the [3]PR in the dark accompanied by periodic fluorescence changes that include near-infrared emission. Moreover, octahedral and spherical nanoparticles are formed through the dissipative self-assembly of the two PRs, and the Golgi apparatus is dynamically imaged using fluorescent dissipative nano-assemblies.

Automated summary

Here we report light-activated convertible pseudorotaxanes (PRs) that can self-assemble and show tunable fluorescence, enabling deformable nano-assemblies. When exposed to light, a specific combination of molecules transform into a transient form, which can thermally relax to its original form in the dark, accompanied by periodic fluorescence changes. The self-assembly of these PRs leads to the formation of octahedral and spherical nanoparticles, which can be used for dynamic imaging of the Golgi apparatus.