A near-infrared colorimetric and fluorescent dual-channel probe for cyanide detection based on dicyanomethylene-4H-pyran

[Display omitted] •A turn-on fluorescent probe for CN– has been designed and synthesized.•The probe detects CN-selectively and sensitively and the LOD of CN– is 1.44 μM.•Response of probe to CN–is the nucleophilic addition of the cyanide coupled with the elimination reaction.•The probe successfully detects cyanide in living cells. A novel dicyanomethylene-4H-pyran-based sensor bearing 2-thiophenecarbonyl as a masking group was established for the detection of cyanide anions. Upon the addition of cyanide, sensor 1 manifested a near-infrared emission band at 717 nm, with an extremely large red-shift (~180 nm) in the absorption spectrum. It also showed an obvious color change from yellow to green. Sensor 1 was used to sensitively measure CN− with low detection limit of 1.44 μM. The stoichiometric ratio between probe and CN− were determined as 1:1, with the association constant of 7.87 × 102 M−1. The reaction mechanism was investigated by ESI-MS, 1H NMR, HPLC, and density functional theory methods. Results indicate that the nucleophilicity of the cyanide catalyzes the elimination of 2-thiophenecarbonyl, which strengthens the intramolecular charge transfer effect of the dicyanomethylene-4H-pyran fluorophore. Furthermore, sensor 1 was found to be efficient in detecting cyanide in the intracellular region of MCF-7 cells.