A lysosome-targeted fluorescent probe for pH sensing and it's applications in food analysis and bioimaging

Abnormal fluctuations in intracellular pH may trigger dysfunction of cells and corresponding tissues, including inflammation, Alzheimer's disease, cancer, and so on. Thus, dynamic monitoring of intracellular pH values and the range of their fluctuations are of great physiological value. In this article, we have synthesized a lysosometargeting fluorescent probe that exhibits intramolecular charge transfer (ICT) as the dominant mechanism. The probe has the advantages of excellent optical response, membrane permeability, and high resolution. In addition, the probe has good linearity over a wide pH range from 2.0 to 10.0, which can detect the pH values in real complex food samples (apple juice, peach juice, black tea, tea pi, and lemon tea). Furthermore, the probe has been successfully applied in targeted imaging of lysosomes for pH changes. To sum up, the probe has capacity to be used for detecting various pH fluctuations in vitro and vivo.