Multianalyte azo dye as an on-site assay kit for colorimetric detection of Hg2+ions and electrochemical sensing of Zn2+ ions
Gargi Dhaka, Gitanjali Jindal, Ranjeet Kaur, Shweta Rana, Akhil Gupta, Navneet Kaur
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
A new tailor-made colorimetric chemosensor, (E)-1-(benzo[d]thiazol-2-yl)-3-(pyridin-3-yldiazenyl)naphthalen-2-ol (1), containing benzothiazole and pyridine moieties connected through an azo (-N=N-) linkage has been designed and synthesized. The synthesized chemosensor displayed an eye-catching color change upon binding to acetate [AcO−;colorless to russet] and mercury (II) [Hg2+;colorless to greenish blue] ions in 9:1 (v/v) aqueous CH3CN (pH 7.0 HEPES buffer).The mechanism of interaction between the chemosensor and the Hg2+/AcO− ions has been confirmed by 1H NMR titration experiments. Moreover, the colorimetric chemosensor 1 displayed potential in-field applications as on-site assay kit and detection of Hg2+ ions in real water samples. Importantly chemosensor 1 gave selective electrochemical response towards Zn2+ ions, enabling simple azo-dye 1 as multichannel chemosensor for colorimetric detection of Hg2+ ions and electrochemical detection of Zn2+ ions.
Absorption, Ligand binding, Chemical stability, Quantitation, Sensors, Materials