Redox-responsive poly(ionic liquid) microgels explored as the building blocks for supramolecular assembly

In this study, poly(ionic liquid) (PIL) microgel functionalized by ferrocene (Fc) was fabricated via a facile one-step cross-linking copolymerization in selective solvent. The results demonstrated that the sizes of PIL microgels could be well-tuned through the feeding ratio of IL monomers to the cross-linker. The presence of Fc groups in PIL microgel was confirmed through ultraviolet–visible (UV–vis), inductively coupled plasma optical emission spectrometer (ICP-OES) and Fourier transform infrared (FT-IR) measurements, as well as cyclic voltammetry (CV) technique. In addition, Fc-anchored PIL microgels were found to be electrochemically active and could respond reversibly to the redox stimulus. As a prototype application, Fc-anchored PIL microgels were explored as the building blocks for the supramolecular self-assembly. Through the host-guest inclusion complexation interaction of Fc group with β-cyclodextrin (β-CD) dimer, PIL microgels could undergo a reversible association and dissociation. Importantly, an enhanced peak current could be achieved when PIL microgel-supported Fc groups were complexed with β-CD dimer. The founding thus pave a way toward fabricating supramolecular systems using nanoparticles as the building blocks, which will find wide applications in smart material, drug delivery and electrochemistry. Ferrocene (Fc)-grafted poly(ionic liquid) (PIL) microgels are prepared easily through an one-step strategy and utilized as the building blocks to achieve supramolecular assembly, which is mediated via host-guest complex interaction. [Display omitted] •Fc-anchored PIL microgels are prepared via one-step synthesis technique.•PIL microgels are electrochemically active and can respond to the redox stimulus.•PIL microgels could undergo a reversible self-assembly through host-guest interaction with β-CD.•An enhanced peak current is observed after complexing PIL microgel with β-CD.