A highly selective optical sensor for the detection of cyanide ions in aqueous solution and living cells

A fluorogenic naphthalene based receptor (NFS) has been successfully generated by preparation from 3-amino-2naphthol and 2-hydroxy-1-naphthaldehyde, it was then characterized. Optical and colorimetric properties of the receptor (NFS) in terms of cyanide (CN-) ions were investigated by several methods including naked-eye detection, UV-vis spectrophotometry and fluorescence spectroscopy. A visual color change from yellow to orangish-pink was observed upon interaction of the receptor with cyanide (CN-) ions in solution, while no color change appeared upon addition of the other anions tested. The detection limit of NFS was calculated as 0.21 mu M without any interaction with other anions tested which is lower than that described by the World Health Organization for CN- ions in drinking water. It can be concluded that the receptor (NFS) was sensitive and rapid enough for the detection of CN- ions in solutions. The interaction between the receptor and CN- ions was also investigated by 1H NMR titration, MALDI-Tof mass spectrometry, and FTIR-AR spectroscopy. NFS was also applied to the bio-imaging of human epithelial cell line (HEK 293) and the cell imaging studies demonstrated that the receptor was capable of detecting cyanide ions in living cells.