A simple imine as a dual-channel chemosensor for detection of CN- and HS- ions via different mechanisms in organic and aquo-organic media

An imine based easy to make receptor (R) has been synthesized and characterized, which senses CN- and HS- ions selectively and sensitively in neat DMSO and H2O:DMSO (60:40 v/v) media. Upon treatment with these ions, the receptor exhibited instantaneous colour change from yellow to colourless and a fluorescence enhancement and these optical changes are easily detected by direct visualization. Further, other competitive anions didn't display any observable colour and fluorescence changes, indicating the receptor's high selectivity towards CN- and HS- ions. The nucleophilic addition of cyanide ion to the imine bond induces an increase in fluorescence, while HS- ion triggered cleavage of the imine bond, producing enhancement in fluorescence in both the media. The limits of detection for CN- and HS- ions were calculated to be 0.9 and 0.7 mu M, respectively, which are lower than the permissible limit of these ions in drinking water set by the World Health Organization (WHO). The receptor has fruitfully been applied for the detection of these ions in live HeLa cells.

Automated summary

An imine-based receptor has been synthesized and characterized for the selective and sensitive detection of CN- and HS- ions in neat DMSO and H2O:DMSO media. The receptor shows instantaneous color and fluorescence changes upon interaction with these ions, with detection limits below the WHO permissible limits. Additionally, the receptor has been successfully applied for the detection of these ions in live HeLa cells.