Acetaldehyde-modified-cystine as an enhanced fluorescent probe for intracellular glutathione imaging

The development of fluorescent probes for detection of glutathione (GSH) has attracted extensive attentions due to its close association with cellular functions and diseases. Herein, a fluorescence enhancement sensing system based on acetaldehyde-modified-cystine (AMC) is reported for the detection of thiols, providing detection limits of 36 and 52 μmol L−1 for GSH and cysteine (Cys) respectively. Importantly, the fluorescence response of AMC is highly selective toward thiols with respect to the coexisting species in real biological matrixes. Considering the fact that GSH levels in cancer cells is significantly higher than those of Cys and other reducing species, the fluorescence enhancing response of AMC in cancer cells is dominated by GSH. Therefore, this provides the possibility for selective intracellular GSH imaging in living cancer cells, i.e., HeLa cells in the present study.