Preparation of metallosupramolecular single-chain polymeric nanoparticles and their characterization by Taylor dispersion

Intramolecular cross-linking of polymers can furnish single-chain polymeric nanoparticles (SCPNs), and the use of reversible non-covalent bonds for cross-linking can potentially provide such nanoparticles with stimuli-responsive properties. Here, we report the synthesis of acrylic polymers that carry pendant 2,6-bis(1′-methyl-benzimidazolyl)pyridine ligands, and use these for the preparation of SCPNs through the complex formation with different types of metal ions. The addition of the polymer to solutions containing Fe²⁺, Zn²⁺, or Eu³⁺ ions at low concentrations reliably furnishes the metal-ligand complexes. In order to demonstrate the formation of single-chain polymeric nanoparticles, conventional characterization techniques were complemented by Taylor dispersion analysis, which proved to be particularly useful to accurately measure the hydrodynamic radii of the dispersed particles, in spite of the formation of a small fraction of larger aggregates.