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Updated: Jun 23, 2026

A Method for Selecting Structure-switching Aptamers Applied to a Colorimetric Gold Nanoparticle Assay
Published on: February 28, 2015
Selective colorimetric sensing of anions in aqueous media through reversible covalent bonding
Dae-Sik Kim1, Yun-Mi Chung, Mieun Jun
1Department of Chemistry and Center for Electro-Photo Behaviors in Advanced Molecular Systems, POSTECH, San 31 Hyoja-dong, Pohang, 790-784, Republic of Korea.
Abstract:
Selective colorimetric sensing of anions in aqueous media has been studied, which involves reversible covalent bonding as key binding interactions. By introducing a simple nitro chromophore into an o-(carboxamido)trifluoroacetophenone ionophore that recognizes anions through reversible covalent bonding, we have realized a complete selectivity in colorimetric sensing of cyanide among competing anions such as fluoride, acetate, and dihydrogen phosphate in aqueous media. Such selectivity is explained by dominant reversible covalent bonding over hydrogen bonding, which leads to indirect internal charge transfer. The sensing system is readily converted into a polymeric analogue, demonstrating its potential applicability to develop a naked eye detection material for highly toxic cyanide ions.
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