Reversible “off–on” fluorescent probe for anions based on a facile two-component ensemble

A specific fluorescent switch for anions was successfully constructed. The novel sensing switch is a two-component ensemble, which was combined using a water-soluble conjugated polyelectrolyte and a boronic acid functionalized pyridine salt. In the ensemble, the polyelectrolyte is used as a fluorescent signal unit, and the pyridine boronic acid acts as receptor and quencher. The two-component ensemble shows a fluorescence reversible “off–on” response toward cyanide and phosphate anions based on different binding ways. Furthermore, the facile design and construction of this ensemble presents a novel opportunity for obtaining an efficient and practical probe.

► A facile ensemble for the detection of phosphate and cyanide ions is described.
► The ensemble is comprised of a polyelectrolyte and a pyridine salt.
► The ensemble shows afluorescence reversible “off–on” response toward anions.
► The mode opens up the way for developing highly efficient and practical probe.