A simple turn-on Schiff base fluorescence sensor for aluminum ion

A simple Schiff base L derived from 2-hydroxy-naphthalene-l-carbaldehyde and benzene-1,2-diamine, was proved to be a turn-on fluorescent probe for the recognition of Al3+, based on photoinduced electron transfer (PET) mechanism. It exhibited a high selectivity for Al3+ over other competing ions (e.g., Hg2+, Ag+, Pb2+, Cu2+, Ba2+, Cd2+, Zn2+, Ni2+, Co2+, Fe2+, Fe2+, Mn2+, Li+, Cr3+, Ca2+, Mg2+, K+, Na+) in EtOH/HEPES buffer (95:5, v/v, pH = 7.2). The complex formation of L-Al3+ was determined to be 1:1 for L and Al3+ in molar. This result was based on the Job plot, H-1 NMR titration and ESI-mass. The binding constant of the complex was 6.53 x 10(3) M-1 with a detection limit of 1.08 x 10(-7) M. The potential applications of L to detect Al3+ in live cells and in environmental water samples were also investigated. The results indicated that L could be a promising probe for Al3+ recognition. (C) 2016 Elsevier Ltd. All rights reserved.