Dual-mode "turn-on" fluorescence and colorimetric probe toward cyanide based on ESIPT and its bioimaging applications

It's important to pay great attention to the detection of CN- due to its high toxicity. Based on ESIPT characteristics, we design, synthesize and characterize the colorimetric and fluorescence "turn-on" probe AHAM to recognize CN-, which has the large Stokes shift (228 nm), exhibits high sensitivity and excellent selectivity. The limit detection of the probe AHAM for CN- was 1.94 x 10-8 M, which was much lower than the standard set by WHO and many previously reported probes. The recognition mechanism between AHAM and CN- was investigated by spectroscopic analysis, 1H NMR titration and mass spectrometry. To our surprise, AHAM could not only identify CN- reversibly, but also recognize CN- accurately in test paper and silica gel plate applications. Furthermore, AHAM was successfully used for fluorescence imaging in C. elegans and mice. It provides the new easy, fast and accurate method to detect CN-.