A novel water-soluble fluorescent probe with ultra-sensitivity over a wider pH range and its application for differentiating cancer cells from normal cells

A novel pH-sensitive fluorescent probe has been designed and synthesized for sensing intracellular pH. This probe showed excellent water solubility, it was sensitive toward the pH range from 4 to 12, and it was especially sensitive in the alkaline environment. During the pH changes from acidic to alkaline environments, the color of solution turned from yellow to purple, thus it can use the difference in color to distinguish between acidic and alkaline systems. The other major features of probe pH-DCN including high selectivity, low toxicity, good reversibility and stability allowed pH-DCN to visualize fluctuations of the pH in the live cells. Moreover, probe pH-DCN have successfully discriminated cancer cells from normal cells by monitoring their different intracellular pH levels.