Sequential displacement strategy for selective and highly sensitive detection of Zn2+, Hg2+ and S2- ions: An approach toward a molecular keypad lock
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.
- Publication:
-
Spectrochimica Acta Part A: Molecular Spectroscopy
- Pub Date:
- February 2019
- DOI:
- 10.1016/j.saa.2018.10.016
- Bibcode:
- 2019AcSpA.208..271P
- Keywords:
-
- Chromofluorescent;
- Salicylidene;
- Thiocarbonohydrazone;
- Macrocycle;
- Zinc;
- Mercury;
- Sulphide;
- Displacement strategy;
- Molecular keypad lock