A highly selective and sensitive turn on optical probe as a promising molecular platform for rapid detection of Zn (II) ion in acetonitrile medium: Experimental and theoretical investigations

Abstract

Abstract A highly Zn2+ ion responsive novel cation sensor (L) based on the dual mechanism (ESIPT/ICT) was designed, synthesized and characterized. The sensor L shows great turn on selectivity for Zn2+ ion in 1:1 stoichiometric manner via rapid color change and 5-fold fluorescence enhancement in CH3CN over other interfering cations. The addition of Zn2+ ion to L, triggers the deprotonation of imidolic and hydroxylic protons of L, which in turn shows an enhanced red shift in both UV–Vis and fluorescence spectra of the sensor. The limit of detection and binding constant obtained are well within those reported for Zn2+ ion. The theoretical calculations were correlated with experimental results to understand the sensing mechanism between host guest interactions and L distinguishes Zn2+ from Cd2+. Furthermore, bioimaging studies were undertaken to investigate practical usefulness of L to recognize Zn2+ ion using HeLa cells.