A mitochondria-targeted fluorescent probe with viscosity sensitivity to distinguish between normal and cancer cells

Viscosity is one of the key factors of the mitochondrial microenvironment, and any abnormal change in the viscosity is not conducive to the normal functioning of the mitochondria. Therefore, it is extremely crucial to monitor the mitochondrial viscosity for disease diagnoses. In this study, a novel fluorescent probe YPE based on twisted intramolecular charge transfer (TICT) was synthesized via simple synthetic steps. The probe has the characteristics of excellent targeting of mitochondria, good adaptation to a wide pH range, outstanding photostability, and good biocompatibility. Furthermore, we used the probe to investigate the changes in the mitochondrial viscosity under various drug stimulations and distinguish between normal and cancer cells via fluorescence imaging. It provides a powerful fluorescence tool for understanding the abnormal changes in the mitochondria. Viscosity is one of the key factors of the mitochondrial microenvironment, and any abnormal change in the viscosity is not conducive to the normal functioning of the mitochondria.