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

A novel supramolecular ME (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 supra molecular molecular AIE gel, PMDP-G, via "exo-wall" pi-pi interactions and host-guest interactions in cyclohexanol solution. Interestingly, PMDP-G shows bright blue-white ME 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" pi-pi interactions and cation-pi interactions. The LODs (limits of lowest detection) of these AIE gels for Fe3+, Hg+, Ag+, F-, and BC are in the range of 7.3 x 10(-10)-9.5 X 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 ME gel PMDP-G could be used as a smart fluorescent display material.