Padhan SK, Palei J, Rana P, Murmu N, Sahu SN. Sequential displacement strategy for selective and highly sensitive detection of Zn
2+, Hg
2+ and S
2- ions: An approach toward a molecular keypad lock.
SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2019;
208:271-284. [PMID:
30340207 DOI:
10.1016/j.saa.2018.10.016]
[Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 10/07/2018] [Accepted: 10/11/2018] [Indexed: 05/14/2023]
Abstract
A thiocarbonohydrazone locked salicylidene based macrocycle ligand L has been synthesized and its ion sensing properties were examined by UV-visible and fluorescence spectroscopy. The macrocycle serves as a highly selective colorimetric sensor for Hg2+ ions while it acts as an excellent fluorescent sensor for Zn2+ ions by exhibiting a green fluorescence at 498 nm even in the presence of interfering ions. A detailed analysis of binding characteristics such as complex stoichiometry, association constant and detection limits of L toward Hg2+ and Zn2+ ions were evaluated by UV-visible and fluorescence experiments which revealed a stronger binding affinity and higher detection limit of L toward the mercury ions. Further, the sequential displacement strategy for the chromofluorogenic detection of Zn2+, Hg2+ and S2- ions by ligand L, has been studied comprehensively. Finally, the ion-responsive fluorescence output signal of L were employed to design a molecular keypad lock which could be accessible by two users having two different set of chemical passwords (inputs) through distinguishable optical trajectories.
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