Th4+ tuned aggregation-induced emission: A novel strategy for sequential ultrasensitive detection and separation of Th4+ and Hg2.

A novel strategy, Th4+ tuned aggregation-induced emission, for sequential ultrasensitive detection and separation of Th4+ and Hg2+ was developed successfully. For demonstration this strategy, we designed and synthesized two tripodal gelators TH (tri-(isoniazid-4-yl)-functionalized trimesic acylhydrazine) and TA (tri-(pyridine-4-yl)-functionalized trimesic amide). The TH and TA could assemble into a stable supramolecular polymer hydrogel THTA-G in DMSO/H2O (3.3:6.7, v/v) binary-solution. The THTA-G does not show aggregation-induced emission (AIE) effect. However, after addition of Th4+ into the THTA-G, the obtained metallogel THTA-GTh shows strong green AIE effect, which indicated that Th4+ could tune the gel generation of AIE effect. Interestingly, the THTA-G could ultrasensitive fluorescently detect Th4+, and the corresponding metallogel THTA-GTh could ultrasensitively detect Hg2+. The detection limits of THTA-G and THTA-GTh for Th4+ and Hg2+ are 8.61 × 10-11 mol/L and 1.08 × 10-11 mol/L, respectively. Additionally, the xerogels of THTA-G and THTA-GTh could separate Th4+ and Hg2+ from aqueous solution with excellent ingestion capacity, and the THTA-G could be used as a writable smart light-emitting material.