A Highly Selective and Sensitive Fluorescent Chemosensor for Detection of Al3+ in Totally Aqueous Media

A fluorescent chemosensor (1) based on 2-hydroxy-1-naphthaldehyde Schiff-base was developed for the detection of Al3+ in 100% aqueous solution. Upon addition of Al3+, a significant fluorescence enhancement was observed, which was not affected by other metal ions including Na+, K +, Ca2+, Mg2+, Mn2+, Co2+, Ni2+, Cu2+, Cr3+, Ag (+), Pb2+, Zn2+, Cd2+, Hg2+, Fe2+ and Fe3+ under weak acid conditions. Moreover, the specific response to Al3+ was visible under natural light. The binding mode between 1 and Al3+ was clarified by ESI-MS and H-1 NMR.