A novel colorimetric chemosensor for multiple target ions in aqueous solution: simultaneous detection of Mn(II) and Fe(II)

We have synthesized a new Schiff base 1 having julolidine moiety, which detects Mn2 + and Fe2 + through naked eye in aqueous solution. The sensor 1 exhibited significant color changes from pale yellow to orange for Mn2 + and to dark green for Fe2 +. The complex formations were proposed to be 1:1 ratio, based on Job plot and ESI-mass spectrometry analysis. The detection limits of Mn2 + and Fe2 + were found to be 7.11 μM and 0.14 μM, respectively, which are below the WHO acceptable limits (manganese: 7.28 μM and iron: 5.36 μM) in drinking water.