A highly selective fluorescent and chromogenic probe for CN- detection and its applications in bioimaging

In this study, 3-ethyl-2-methylbenzothiazolium iodide and nitrophenyl-2-furancarboxaldehyde were used to synthesize a new fluorescent and chromogenic dual channel signal cyanide ion probe M, which showed high selectivity towards CN analysis and strong antijamming capability towards other anions. When CN is present in the solution, probe M indicates an obvious blue shift in UV-vis absorbance spectra, which can be observed clearly by unaided eyes. The limits of detection (LODs) of CN based on fluorescence and UV-vis absorbance were 0.11 mu M and 0.16 mu M, respectively. The mechanism of fluorescent and chromogenic cyanide ion detection refers to the nucleophilic addition of cyanide ion to carbon atom of-C-N-in the benzothiazole. The a-conjugation and ICT transition between furfural and benzothiazole were broken due to this non-reversible reaction, resulting in the color change and fluorescent characterizations. In addition, probe M also showed the excellent optical properties and high biocompatibility, which enables the practical application of CN- tracing in biomedical systems.