A fluorescent probe to detect thiol-containing amino acids in solid tumors

Early detecting of cancer is critical to provide proper treatment and to improve survival of patients. Here, we reported a highly sensitive ratiometric (yellow emission (550 nm) to blue emission (496 nm)) fluorescent probe 1 developed for detection of thiol-containing amino acids. This probe successfully eliminates interference from background autofluorescence, and discriminates between human carcinoma and normal cells by detecting intracellular thiol levels in living cells (P < 0.05). Furthermore, the ability of the probe to identify growing tumors by measuring GSH in the tissues as well as in the fresh blood of tumor xenograft mice. Additionally, the ratio of the emission intensity at two different wavelengths can provide quantitative analysis of glutathione (GSH) in the living systems. It suggests that it represents a promising prognostic and diagnostic marker, with extensive and simple potential clinical applications.