Ratiometric Fluorescent Sensor for Silver Ion and Its Resultant Complex for Iodide Anion in Aqueous Solution

In aqueous solution, sensor DQAg can selectively detect Ag+ based on inhibition of the resonance, demonstrating a large hypsochromic shift of 84 nm and remarkable changes in the ratio (F-481 (nm)/F-565 nm) of the emission intensity (R/R-0 up to 26-fold). Furthermore, the resultant Ag-DQAg also displays a ratiometric and highly selective response to iodide anion over other anions due to the liberation of DQAg from the complex by precipitating AgI.