Carboxamide-based Fluorescent Sensor for the Detection of Mg2+ and Ni2+ Ions

Abstract

In this work, pyridine-2,6-dicarboxamide based ligand was synthesized by reacting pyridine-2,6-dicarboxylic acid with a thiazole derivative. The synthesized ligand was characterized by 1H NMR and 13C NMR, IR spectroscopic and mass spectrometry. The UV-visible spectrum accompanied with fluorescent spectral studies, binding constants and limit of detection proved efficient sensing abilities. The ligand was found to bind with one equivalent of an M2+ ion as validated by Job’s plot and binding parameters. The novel fluorescent probe based on amide ligand exhibits precise and selective response to Mg2+ and Ni2+ ions in HEPES buffer solution showing the detection limit to be 2.1502 × 10–8 mol/L and 4.8007 × 10–8 mol/L, respectively. The binding stoichiometry of amide ligand with Mg2+ and Ni2+ was estimated by Job’s plot method and found to be 1:1, which is further confirmed by mass spectrometry.