Spectroscopic detection of metals ions using a novel selective sensor

摘要

Colorimetric chemosensors are simple, economical and practical optical approach for detecting toxic metal ions (Hg~(2+), Pb~(2+), Ni~(2+), etc.) in the environment. In this work, we present a simple but highly specific organic compound 4-chloro-2-((E)-((E)-3-(4-(dimethylamino)phenyl)allylidene)amino)phenol (LI) that acts as a colorimetric sensor for divalent metal ions in H_2O. The mechanism of the interaction between LI and various metal-ions has been established by UV-vis absorption and emission spectroscopic experiments that indicate favorable coordination of metal ions with LI in different solvents. Experimental results indicate that the shape of the electronic transition band of LI (receptor compound) changed after the interaction with divalent metal-ions, such as Hg~(2+), Pb~(2+), Mn~(2+), Co~(2+), Cu~(2+), and Ni~(2+) in aqueous solution. We found that LI have a considerable selectivity for Ni~(2+) ions, even in presence of other metals ions when mixtures of DMSO/H_2O as are used as solvents. LI, which has been targeted for sensing transition metal ions, exhibits binding-induced color changes from yellow to pink observed even by the naked eye in presence of Ni~(2+) ions.