A multifunctional fluorescent probe: Selective visualization of mitochondria and tumor cells with viscosity/polarity responsiveness

Abstract

The generation of cancer cells is often accompanied by significant changes in their microenvironment, including increased viscosity, decreased polarity, elevated levels of reactive oxygen species and reduced pH. These alterations are significantly distinct from the microenvironment of normal cells. In response to the characteristics of cancer cells, we designed and synthesized a red fluorescent probe that responds to mitochondrial viscosity and polarity. The positively charged pyridine group facilitates targeting of the mitochondria, while the sulfonic acid group enhances water solubility. The probe exhibits favorable spectral properties, demonstrating significant aggregation-induced emission (AIE) characteristics, excellent water solubility, responsiveness to viscosity changes, and strong photostability. Through cellular experiments and mouse imaging technology, this probe displayed high localization to the mitochondrial membrane and effectively monitored changes in mitochondrial polarity and viscosity. More importantly, due to the differences in mitochondrial viscosity and polarity between normal and cancer cells, the probe can selectively identify cancer cells, offering potential for tumor-specific imaging. This groundbreaking discovery paves the way for advancements in tumor diagnosis, contributing to more accurate tumor identification.