A isophorone based colorimetric and ratiometric probe: Synthesis and rapid detection of cyanide in aqueous medium and its application in bioimaging

A simple colorimetric and fluorescent sensor for cyanide based on phenolic substituted dicyanoisophorone derivative (2) has been synthesized. The absorption spectra of chemosensor 2 showed large bathochromic shift (ca. 240 nm) upon titration with CN- while the solution color changed from yellow to green. The absorption ratios (A685/A446) responses of chemosensor 2 showed a favorable linear relationship with the CN- concentration and the detection limitation had been calculated to be 0.15 mu M. Meanwhile, the fluorescence intensity of 2 can be quenched upon reacting with CN- over other anions. More importantly, chemosensor 2 can react instantaneously with cyanide in aqueous solution, and to visualize CN- in living HeLa cells by means of dramatic decrease of fluorescence intensity. Thus, the present sensor could be applicable in detecting cyanide ion both in natural water samples and biological systems conveniently.