Rhodamine B targeted lysosome pH fluorescent probe with cysteine ethyl ester structure and application of rhodamine B targeted lysosome pH fluorescent probe

The invention discloses a rhodamine B targeted lysosome pH fluorescent probe with a cysteine ethyl ester structure, wherein the rhodamine B targeted lysosome pH fluorescent probe has the structure as shown in a formula (I). Meanwhile, the invention discloses an application of the probe as a living cell lysosome pH fluorescent probe. Experiments show that the probe provided by the invention does not generate fluorescence under the neutral and alkaline conditions, the fluorescence intensity is rapidly enhanced along with the reduction of the pH value of the solution, is up to the maximum value when the pH value is about 4.0 and is enhanced by about 150 times when the pH value ranges from 7.51 to 3.53, and the probe has favorable antijamming capability and reversibility in the presence of various metal ions. An intracellular colocalization experiment and an interlysosome pH regulation experiment prove that the probe can specially mark a lysosome and sensitively monitor the small change of the interlysosome pH va