A Tetraphenylethene-Based Rhodamine Hydrazone Chemosensor for Colorimetric and Reversible Detection of Cu~(2+)

摘要

A tetraphenylethene (TPE) based rhodamine hydrazone com- poundRbTS has been synthesized by condensation of 2-hy- droxy-5-(1,2,2-triphenylvinyl)benzaldehyde and rhodamine B hydrazide. It exhibitsaggregation-induced emission(AIE)be- havior when the water fractionis more than 40%. In Tris-HCl buffered EtOH-H_2O solution (1:2, v:v), the chemosensor RbTS shows remarkably enhanced absorbance intensity and visual color changes from colorless to purple after the addition of Cu~(2+). The response is based on the spirolactam opening proc- ess and formation of a 1:1 metal-ligand complex. The absorb- ance signals of RbTS can be restored by addition of EDTA into the solutions of RbTS-Cu~(2+), which demonstrated that the bind- ing of RbTS and Cu~(2+) is chemically reversible. The detection limit of RbTS for Cu~(2+) is below 10~(-6) M in the neutral aqueous system.The results indicate that RbTScould be used as a suit- able “naked eye” and reversible indicator for Cu~(2+) ions.