Aggregation-induced emission supramolecular organic framework (AIE SOF) gels constructed from tri-pillar[5]arene-based foldamer for ultrasensitive detection and separation of multi-analytes

Abstract

In this study, a novel aggregation-induced emission supramolecular organic framework (AIE SOF) with ultrasensitive response, termed FSOF, was constructed using a tri-pillar[5]arene-based foldamer. Interestingly, benefiting from the noise signal shielding properties of FSOF as well as the competition between the cation⋯π and π⋯π interactions, the FSOF shows an ultrasensitive response for multi-analytes, such as Fe³⁺, Hg²⁺ and Cr³⁺. The limits of detection (LODs) of the FSOF for Fe³⁺, Hg²⁺ and Cr³⁺ are in the range of 9.40 × 10⁻¹⁰–1.86 × 10⁻⁹. More importantly, the xerogel of FSOF exhibits porous mesh structures, which could effect high-efficiency separation above metal ions from their aqueous solution, with adsorption percentages in the range 92.39–99.99%. In addition, by introducing metal ions into the FSOF, a series of metal ions coordinated supramolecular organic frameworks (MSOFs) were successfully constructed. Moreover, MSOFs show selective fluorescence “turn on” ultrasensitive detection CN⁻ (LOD = 2.12 × 10⁻⁹) and H₂PO₄⁻ (LOD = 1.78 × 10⁻⁹). This is a novel approach to construct SOFs through a tri-pillar[5]arene-based foldamer, and also provides a new way to achieve ultrasensitive detection and high-efficiency separation.