A New Rhodamine-Based Colorimetric Cyanide Chemosensor: Convenient Detecting Procedure and High Sensitivity and Selectivity

By applying an indirect strategy, a new rhodamine-based dye (1) was successfully developed as a colorimetric chemosensor for the sensitive detection of cyanide. In the presence of copper ions, the colorless solution of compound I changed to magenta: however, upon the addition Of trace cyanide, the magenta color faded to colorless immediately, with a detection limit as low as 0.013 ppm (Delta A = 0.054), much lower than the Maximum Contaminant Level for cyanide In drinking water (0.20 ppm) set by the US Environmental Protection Agency. Other anions, including Cl-, l(-), lO(3)(-), SO42-, NO2-, Br-, H2PO4-, F-, SCN-, HSO4-, and ClO4-, had nearly no influence on the probing behavior of dye I toward cyanide.