Near-Infrared Probes Designed with Hemicyanine Fluorophores Featuring Rhodamine and 1,8-Naphthalic Derivatives for Viscosity and HSA Detection in Live Cells.

This paper presents the development of near-infrared (NIR) fluorescent probes, and , engineered from hemicyanine dyes with 1,8-naphthalic and rhodamine derivatives for optimized photophysical properties and precise mitochondrial targeting. Probes and exhibit absorption peaks at 737 nm and low fluorescence in phosphate-buffered saline (PBS) buffer. Notably, their fluorescence intensities, peaking at 684 () and 702 nm (), increase significantly with viscosity, as demonstrated through glycerol-to-PBS ratio experiments.