A new dihydrazone based "turn on" fluorescent sensor for Zn(II) ion in aqueous medium

Abstract

A new simple dihydrazone based colorimetric and fluorescent "turn-on" chemosensor (disalicyladehyde succinoyldihydrazone, I) for Zn(II) was designed and synthesized. The photophysical behavior of the ligand and metal coordinated complex was characterized by steady state and time-resolved fluorescence, density functional theory calculation in combination with 1H NMR and mass spectroscopy results. The compound acts as a highly selective and sensitive detector of Zn(II) in aqueous medium with almost six times increase in fluorescence intensity. The optimum condition for sensing ability of I with a detection limit of ca. 2 μM of Zn(II) was found at solution pH 8.6 and at excitation wavelength of 380 nm. The other interfering elements, including Cd(II), show either no or very little change in fluorescence intensity under similar experimental conditions. © 2014 Elsevier B.V. All rights reserved.