A New Fluorescent Probe Based on Aggregation Induced Emission for Selective and Quantitative Determination of Copper(II) and its Further Application to Cysteine Detection

A new fluorescent chemosensor 2,2'-((1E,1E)-hydrazine-1,2-diylidenebis(methanylylidene))bis(4-(1,2,2-triphenylvinyl)phenol) TPESAA incorporated with salicylaldehyde azine motif was developed based on aggregation-induced emission (AIE). The probe TPESAA was prepared from 4-hydroxy tetraphenyl ethylene which underwent formylation followed by condensation with hydrazine hydrate. It showed ratiometric fluorescence quenching behavior to Cu2+, which could induce naked-eye color changes from colorless to pale yellow. Moreover, it displayed excellent sensitivity and selectivity toward Cu2+ without interference from other metal ions. The extent of quenching is dependent on the concentration of Cu2+ in the range of 0.5-7.5 mu M, and a remarkable detection limit (30.9 nM) can be achieved. Furthermore, the obtained Cu2+ complex could be applied to quantitative determination of cysteine in the range of 0.2-2 mu M with a good linear relationship.