A Fluorescent Chemosensor for Al3+ Based on CO Isomerization Derivated from Curcumin

A simple and nontoxic fluorescent chemosensor of di- O -methyl curcumin has been prepared from curcumin. The sensor exhibited selective and sensitive fluorescent responses toward Al 3+ over a wide range of metal ions, such as Mn 2+ , Ce 3+ , Pt 2+ , Sn 4+ , Hg + , Sb 3+ , K + , Ca 2+ , Mg 2+ , Ba 2+ , Cu 2+ , Ni 2+ , Na + , NH 4 + , Ag + , Pb 2+ , Zn 2+ , Fe 2+ , Fe 3+ , Hg 2+ and Cr 3+ in ethanol/water. The free ligand showed quite weak fluorescence emission due to the isomerization of CO double bond in the excited state, however, after addition of Al 3+ , fluorescence emission results in a prominent fluorescence enhancement.