A dansyl-based optical probe for detection of singly and doubly charged anions

Abstract

This paper reports the synthesis of a new molecule, 5-(dimethylamino)naphthalene-1-sulfonic acid 2,3-bis(3-phenylureido)phenyl ester (1), as an optical probe for anions. The effect of the presence of various anions on the spectroscopic properties of 1 was examined using UV–vis absorption spectroscopy, fluorescence and ¹H NMR titration experiments. Strong binding of 1 to carboxylate, oxalate, cyanide and dihydrogen phosphate anions resulted in an increase in the emission of 1 and changes in its ¹H NMR chemical shifts. Binding constants of 1 to anions were also calculated based on the binding isotherms derived from the spectroscopic titrations.

Keywords:

• Anion sensor
• fluorescent sensor
• oxalates
• bisurea
• dansyl

Acknowledgements

The authors are grateful for the financial support of the American University of Sharjah, UAE (FRG11-02-07).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was financially supported by the American University of Sharjah, UAE [grant number FRG11-02-07].