Dicyanisophorone-based viscosity fluorescent probe and its fluorescence imaging in cells and zebrafish

Cellular viscosity is a critical parameter for maintaining normal cellular functions, and its abnormalities are associated with the occurrence and development of various diseases. Therefore, real-time monitoring of cellular viscosity is of significant importance for understanding viscosity-related biological functions and revealing the pathological mechanisms of diseases. In this study, we developed a novel fluorescence probe (IP-HBO) by hybridizing dicyanisophorone with 2-(2-hydroxyphenyl)benzoxazole for monitoring of cellular microenvironment and viscosity changes in zebrafish. The probe IP-HBO combines the principles of molecular rotors and enhanced solid-state fluorescence properties, demonstrating highly specific responsiveness to viscosity, long-wavelength emission, large Stokes shift, and excellent photostability. It has been successfully employed for fluorescence imaging of viscosity in live HeLa cells and zebrafish. The construction of this probe provides a new tool for gaining insights into viscosity-related biological processes and disease mechanisms within cells.