A Novel D-π-A Triphenylamine-Based Turn-on Colorimetric and Ratiometric Fluorescence Probe for Cyanide Detection

A novel colorimetric fluorescent chemosensor TP1 with a D-pi-A structure for the detection of (cyanide) CN- has been developed. TP1 is capable of showing high selectivity and sensitivity towards CN- over a wide range of other interfering anions. After reaction with CN-, TP1 shows a significant blue-shift of absorption peak from 514 to 437 nm, which induces color changes from amaranth to yellow. Non-fluorescent TP1 upon interaction with CN- exhibits a ca. 17-fold fluorescence enhancement at 551 nm, resulting in strong orange emission. The sensing mechanism of TP1 recognizes CN- which undergoes a nucleophilic addition reaction. Moreover, the detection limit of the probe TP1 towards CN- is 1.4 x 10(-8) M, which is far lower than the WHO guideline of 1.9 mu M cyanide for drinking water. In addition, the cell imaging experiments certify that TP1 can be successfully applied as a bioimaging agent for monitoring CN- in pheochromocytoma cell (PC12).