Naked-eye detection of Cu (II) and Fe (III) based on a Schiff Base Ruthenium complex with nicotinohydrazide

A cyclometalated ruthenium (II) complex1[(Ru (Phen)(2)(Pbznh)]+PF6-(Phen = 1,10-phenanthroline and Pbznh = N-(4-(pyridine-2-yl)benzylidene) nicotinohydrazide) with nicotinohydrazide as a functional group was synthesized and characterized. Changes of its absorption spectra and color induced by Cu(2+)and Fe(3+)were systematic investigated. The results demonstrated that complex1could be served as a colorimetric probe to fast, selective and sensitive detection of Cu(2+)and Fe(3+)both in acetonitrile and filter paper based strips. Upon addition of Cu(2+)and Fe(3+)to solution of probe1, solution color changed from pink to colorless and light yellow respectively, and their corresponding detection limit were calculated to be 3.26 x 10(-8)M and 3.12 x 10(-7)M. Moreover, color of test papers with1changed from pink to colorless/yellow when Cu2+/Fe(3+)were dropwise added. Therefore, it can be used as a desirable 'naked-eye' indicator candidate for Cu(2+)and Fe3+.