Supramolecular Aggregation-Induced Emission Gels Based on Pillar[5]arene for Ultrasensitive Detection and Separation of Multianalytes

A novel supramolecular AIE (aggregation-induced emission) gel (PMDP-G) based on pillar[5]­arene which could ultrasensitively detect and separate multianalytes was efficiently constructed. First, a novel supramolecular gelator, PM (host), and a functionalized pillar[5]­arene, DP (guest), were successfully designed and synthesized. Then, host PM and guest DP could construct a stable supramolecular AIE gel, PMDP-G, via “exo-wall” π–π interactions and host–guest interactions in cyclohexanol solution. Interestingly, PMDP-G shows bright blue-white AIE and the fluorescence quantum yield is about 60%. Moreover, PMDP-G could carry out ultrasensitive detection and separation of multianalytes such as Fe3+, Hg2+, Ag+, F–, and Br– by the competition between “exo-wall” π–π interactions and cation−π interactions. The LODs (limits of lowest detection) of these AIE gels for Fe3+, Hg2+, Ag+, F–, and Br– are in the range of 7.3 × 10–10–9.5 × 10–9 M, indicating high sensitivity. More importantly, the xerogel of PMDP-G could adsorb and separate Fe3+, Hg2+, and Ag+ from aqueous solution with nice adsorption property, and the adsorption rates are in the range of 90.12–99.95%. Meanwhile, supramolecular AIE gel PMDP-G could be used as a smart fluorescent display material