A highly sensitive and reusable cyanide anion sensor based on spiropyran functionalized polydiacetylene vesicular receptors

Abstract

A great deal of effort has been invested in developing easy-to-use colorimetric and fluorometric probes for the detection of cyanide anions (CN⁻) due to their extremely toxic effects. However, most of the current probes are insoluble in water, limiting their practical application. Herein, the fabrication of spiropyran functionalized polydiacetylene (SPFPDA) vesicles for selective and sensitive detection of CN⁻ in HEPES buffered aqueous solution is described. The present detection limit for CN⁻ is 5 × 10⁻⁷ M. Their excellent selectivity and sensitivity are mainly attributed to the nucleophilic addition reaction of CN⁻ with the spiropyran group at the lipid–solution interface, which could subsequently perturb the PDA backbone and induce colorimetric changes of the solution. In addition to the colorimetric detection, the above SPFPDA vesicles could also serve as sensitive and reusable fluorometric probes for CN⁻ detection in aqueous media.