Supramolecular AIE polymer-based rare earth metallogels for the selective detection and high efficiency removal of cyanide and perchlorate

Abstract

Two novel supramolecular AIE polymer-based rare earth metallogels (PT-GEu and PT-GTb) were rationally designed and synthesized for the efficient detection and separation of cyanide (CN⁻) and perchlorate (ClO₄⁻). PT-GEu and PT-GTb were prepared by introducing Eu³⁺ and Tb³⁺ into a novel supramolecular polymer (PT-G), which was constructed by the assembly of o-phthalimide functionalized pillar[5]arene host PM and tri-amide guest TH. The supramolecular polymer PT-G shows strong yellow aggregation-induced emission (AIE). Interestingly, after coordination with Eu³⁺ or Tb³⁺, the obtained AIE polymer-based rare earth metallogels (PT-GEu or PT-GTb) show “turn-off” AIE. Interestingly, PT-GEu and PT-GTb exhibit selective and sensitive fluorescent “turn-on” recognition for CN⁻ and ClO₄⁻, respectively. The lowest detection limits are 3.36 × 10⁻⁶ M for ClO₄⁻ by PT-GEu and 5.96 × 10⁻⁸ M for CN⁻ by PT-GTb. In addition, the xerogel of PT-GEu and PT-GTb shows nice separation properties for ClO₄⁻ and CN⁻, the adsorption rate of these rare earth metallogels for ClO₄⁻ and CN⁻ reached up to 92.86% and 93.33%. Moreover, ion detection test kits were prepared based on these rare earth metallogels, which rapidly detect CN⁻ and ClO₄⁻.