Development of a novel fluorescent probe for the Selective and sequential imaging of fluoride and hypochlorite.

Fluoride (F^-) are common in the environment and are beneficial in moderate amounts but can be harmful at high concentrations, leading to conditions such as fluorosis influenced by reactive oxygen species (ROS), including hypochlorite (ClO^-). This study introduces PZ-DT, a novel fluorescent probe with a phenothiazine core, designed for the sequential detection of F^- and ClO^-. PZ-DT emits orange-red fluorescence with a Stokes shift greater than 200 nm upon F^- detection, demonstrating excellent selectivity and sensitivity, boasting a quantum yield of 19.33 % and a detection limit of 0.71 μM. Upon interaction with F^-, PZ-DT forms PZ-F, which exhibits a blue shift in fluorescence upon ClO^- detection, maintaining a Stokes shift of over 100 nm, a quantum yield of 36.2 %, and a detection limit of 19.97 nM. In serum analysis, PZ-DT shows a linear relationship between fluorescence intensity and F^- concentration, enhancing its potential for quantitative analysis. In cellular imaging, PZ-DT highlights F^- in the red channel and ClO^- in the green and blue channels, allowing clear visualization of F^- and ClO^- interactions at the cellular level. In live mouse models, PZ-DT facilitates the visualization of F^- dynamics and exposure decay, providing insights into its metabolic processes and potential health effects. These characteristics underscore its utility in the early diagnosis of fluoride-related diseases.