A new Cu2+-selective self-assembled fluorescent chemosensor based on thiacalix[4]arene

A new ON–OFF fluorescent chemosensor for Cu2+ ions was prepared through self-assembly inside Triton X-100 micelles of p-tert-butylthiacalix[4]arene (TCA) and perylene in water solution. This thiacalix[4]arene-based self-assembled fluorescent chemosensor could realize the direct sensing of Cu2+ ions in aqueous solution. Addition of Cu2+ ions could result in a quenching of the fluorescence emission of perylene inside the micelles, which is ascribed to intramicellar complex-fluorophore electron-transfer or energy-transfer effects induced by the complexation of TCA with the Cu2+ ions. Cu2+ ions can be detected selectively in the presence of other metal ions (Zn2+, Pb2+, Cd2+, Mn2+, Ni2+, Al3+, Na+, K+, Ca2+ and Mg2+) and its concentration in the submicromolar range can be almost linearly determined according to the fluorescence quenching.