A new dibenzothiophene-based dual-channel chemosensor for cyanide with aggregation induced emission

[Display omitted] •A new fluorescent turn-off sensor DTI for CN– detection is reported.•AIE activity of DTI was investigated by fluorescence (FL) spectra.•The CN– detection exhibited high selective, excellent sensitive, fast response time and wide pH response range.•Test strips demonstrated sensor DTI could be used as an optical solid-state sensor for CN–. Based on dibenzothiophene fluorophore, a new colorimetric and fluorescent sensing material 2-(dibenzothiophenyl-4-ethenylidenyl)-1,3-indanedione (DTI) was developed, which was a favorable turn-off fluorescent sensor of monitoring CN– ion at extremely low detection limit (0.14 μM) in 99 % aq. DMSO solution. The response mechanism of DTI towards CN– could put down to nucleophilic attack of cyanide group (CN–) toward the double-bond between the dibenzothiophene and the 1,3-indanedione units, which breaking intramolecular charge transfer (ICT) process. This mechanism was proposed by 1H NMR, Job’s titration and DFT calculation, leading to a significant fluorescence attenuation and a visual color change. The absorption and emission experiments demonstrated that it showed highly sensitive, selective and good stability for CN– in DMSO/H2O (1:99, v/v). Moreover, DTI displayed high effectiveness in monitoring the CN– in test strips achieved to conveniently determinate CN– by naked-eye without any instruments.