An NIR Molecule-based “On–Off” Fluorescent and Colorimetric Sensor for Cyanide Anions

A simple triphenylamine-based molecule P2 was developed as a near-infrared (NIR) “on–off” fluorescent and colorimetric sensor to detect cyanide anions. The nucleophilic attack of cyanide (CN−) onto the dicyanovinyl group blocks the intramolecular charge-transfer process in the molecule. As a result, the fading of the solution color and a rapid quenchable NIR fluorescent response to cyanide ions could be clearly observed upon adding CN− into P2 solution. The detection limit was calculated to be 0.46 nM.