A novel AIE chemosensor based on a coumarin functionalized pillar[5]arene for multi-analyte detection and application in logic gates

Aggregation induced emission (AIE) active molecules are widely applied for multi-analyte detection due to their unique advantages over conventional fluorescent probes. Herein, a novel coumarin functionalized pillar[5]arene (PX) has been designed and synthesized. It has strong AIE activity, and the fluorescence quantum yield ofPXturned out to be 35.0% in DMF/H2O (7 : 3, v/v) binary solution (1.0 x 10(-4)M). Meanwhile, the optimized structure ofPXwas obtained by theoretical calculation at the B3LYP/6-311G level. Interestingly, thePXdisplays high sensitivity to multiple analytes, such as Fe(3+)and Ba2+. The limits of detection (LODs) ofPXfor Fe(3+)and Ba(2+)are 1.67 x 10(-7)M and 5.89 x 10(-8)M, respectively. In addition, by introducing metal ions into the AIE chemosensor ofPX, a metal-coordinated chemosensor (PX-M) was obtained. ThePX-FeandPX-Bashow selective fluorescence "turn on" detection of H2PO4-(LOD = 1.50 x 10(-7)M) and CN-(LOD = 6.20 x 10(-7)M), respectively. The multi-analyte detection mechanism ofPXwas based on multiple competitions of "exo-wall pi-pi" interactions and cation-pi interactions. Notably, we have prepared logic gates controlled by Fe3+/Ba(2+)and H2PO4-/CN(-)at the molecular level, which can quickly and efficiently detect ions in aqueous solutions. Moreover, we also prepared test films, and an Fe(3+)test kit was prepared by loadingPXon a silica gel plate. This study provides a new way for multi-analyte detection.