Probing the Local Polarity in Biocompatible Nanocarriers with Solvatofluorochromism of a 4-Carbazole-1,8-naphthalimide Dye

The study of local polarity at the nanoscale is crucial importance for development smart drug delivery systems and photonic materials frequently accomplished with use luminescent tracer dyes. Nile Red often used this purpose, owing to its polarity-sensitive internal charge transfer transition, but performance affected by specific solute-solvent interactions that prevent widespread applicability. Herein, we develop a new 1,8-naphthalimide dye strong charge-transfer transition results in large dipole moment change upon excitation. This leads luminescence properties high sensitivity solvent polarity, are independent or inductive interactions. These explored probe biocompatible nanocarriers. was effective probing polymeric nanoparticles, allowing accurate calculation descriptors dielectric constants.