Dual-channel fluorescent probe for simultaneous monitoring of polarity and viscosity in live-cell nucleus and sewage water

Abstract

Nuclear polarity and viscosity are critical for maintaining proper nuclear function, including gene expression and chromatin organization. Disruptions in these physical properties can lead to impaired nuclear transport and altered signaling pathways, which are linked to diseases such as cancer and neurodegenerative disorders. We have designed a naphthalimide-based fluorescent “rotor” capable of sensing both viscosity and polarity. Interestingly, the probe Nu-PV exhibited an emission peak at 525 nm in the nonpolar solvent dioxane while in contrast, it displayed a red-shifted emission maximum at 602 nm in environments with high viscosity (glycerol). The probe is chemically stable, non-reactive with other analytes, and non-toxic. It detected changes in viscosity and polarity across various chemical industry samples. It selectively detects the nonpolar components within the nucleus and has shown that nuclear polarity decreases under conditions such as oxidative stress, starvation, and apoptosis. This suggests that probe Nu-PV can effectively monitor changes in nuclear polarity during disease-related states, potentially aiding in the development of treatments to address cellular abnormalities.