A special o-dialdehyde fluorescent probe simultaneously sensing Hcy, GSH and its application in living cells and zebrafish imaging

The development of fluorescent probes enabling to distinguish Cys, Hcy and GSH has always been a considerable challenge, in particular the distinction of Hcy and other two biothiols, because Hcy has a very similar structure with Cys and a relatively lower concentration in living organisms. In this work, a special o-dialdehyde fluorescent probe, quinoline-2,3-dicarboxaldehyde (QDA), has been synthesized and demonstrated superior performance in differentiating detection of Hcy and GSH, which is different from the previous reported o-dialdehyde probes specifically detecting GSH. Furthermore, the probe can selectively distinguish Hcy and GSH from different signal channels in living cells and zebrafish, meaning it has great potential in biological applications. This finding will provide a novel idea for the design of fluorescent probes to distinguish biothiols.