AIE based “on-off” fluorescence probe for the detection of Cu2+ ions in aqueous media

A simple hydrazine carboxamide derivative with intramolecular charge transfer and aggregation induced emission (AIE) properties have been designed and synthesized. The derivative (Probe 1) shows typical AIE characteristic emission in THF-water mixtures and emits yellowish orange color on reaching the water fraction 98%. The probe molecule show selective sensing response for Cu2+ ions via fluorescence turn-off mechanism in aqueous media over other metal ions. The emission changes towards Cu2+ ions that could be clearly observed by the naked eyes under 365 nm UV lamp promote the probe molecule as a promising candidate for practical utilization. Furthermore, from the fluorescence titration data, the detection limit for Cu2+ ions was found to be 0.44 μM.