Colorimetric and near infrared fluorescent detection of cyanide by a new phenanthroimidazole–indolium conjugated probe

Abstract

In this paper, a new dual colorimetric and fluorescent probe for cyanide anions was developed. This probe contains an electron-donating phenanthroimidazole moiety and a strong electron-withdrawing indolium derivative. The detection of cyanide was performed via the fast nucleophilic attack of cyanide on the indolium group of the probe, resulting in a rapid sensing process for cyanide with obvious color and fluorescence (at two different emission channels, one in the visible region and one in the near infrared region) signal changes, and with high selectivity and sensitivity. The detection limit was found to be 26 nM in aqueous solution, and the application of this probe for cyanide detection in simulated wastewater samples was investigated.