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Smart Colorimetric Chemosensors for Multi‐Analyte Signaling: Recognition of Heavy Metal Ions in an Aqueous Medium and DFT Studies
Author(s) -
Tekuri Venkatadri,
Mohan Makesh,
Trivedi Darshak R.
Publication year - 2020
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.202000856
Subject(s) - metal ions in aqueous solution , selectivity , chemistry , detection limit , ion , aqueous solution , metal , analyte , schiff base , stoichiometry , inorganic chemistry , analytical chemistry (journal) , stereochemistry , chromatography , organic chemistry , catalysis
A Schiff's base colorimetric chemosensors R1 – R3 consist of carbohydrazide, and heterocyclic aldehydes have been designed and synthesized for sensing of heavy metal ions. Synthesized receptors were well characterized by various standard spectroscopic techniques. The receptor R1 exhibited multi‐ion selectivity for Cd 2+ , Hg 2+ , Pb 2+ , Cu 2+ ions and showed lowest detection limit of 1.9 ppb, for Cd 2+ & Hg 2+ ions. The receptors R2 and R3 displayed dual ion selectivity ( R2 for Hg 2+ , Cu 2+, and R3 for Cu 2+, AsO 2 – ions) in an aqueous medium at ppb levels. The UV–Vis and colorimetric studies confirmed the selectivity and sensitivity of chemosensors R1–R3 in the presence of other interfering metal ions. Further, using the B–H plot, FT‐IR, and mass analysis data, the binding modes, stoichiometric ratios of receptors R1–R3 with the metal ions were investigated. The estimated association constant values were found to be 10 4 to 10 5 M –1 /M –2 . The experimental results are well concordant with that of calculated theoretical DFT results. The receptors R1–R3 exhibited good sensitivity and selectivity compared to literature reports and successfully demonstrated for test strip applications.