ESIPT-Induced Carbazole-Based AIEE Material for Nanomolar Detection of Cu2+ and CN- Ions: A Molecular Keypad Security Device

Herein, we have designed and synthesized a new diimino dicarbazole derivative, 3, which exhibits the phenomenon of aggregation-induced emission enhancement (AIEE) due to the persistence of the excited-state intramolecular proton transfer phenomenon. The aggregates of AIEE-active material 3 selectively sense Cu2+ ions in the nanomolar range and mediate the conversion of Cu2+ ions to Cu nanorods. The ensemble of aggregates of 3 and Cu nanorods were further utilized for selective sensing of CN- ions. In addition, the fluorescence behavior of the system generates the formation of a molecular keypad security device. The keypad security device, based on AIEE material, adds to the complexity of the lock and makes it more efficient.