Cyanofuran-based ratiometric fluorescent probe for monitoring hypochlorite and cupric ion in cells and in vivo

Hypochlorite (ClO−) mediates various physiological processes and diseases as a reactive oxygen species. The visualization of the concentration changes of endogenous hypochlorite in cells and in vivo faces great challenges due to the single-signal (spectrum) variation. In this study, a multifunctional ratiometric fluorescent probe IBA was designed and developed for analyzing hypochlorite and Cu2+ independently through a synergetic FRET-PET mechanism. The sensor displayed excellent capacities in anti-interference capacity and sensitivity during the analysis processes of hypochlorite and Cu2+. In particular, IBA showed different fluorescence signal for hypochlorite and Cu2+ meeting the need of independent analysis. And taking advantage of excellent optical properties of the probe in detecting hypochlorite, it successfully monitored the fluctuation of exogenous and endogenous hypochlorite in A549 cells. Moreover, IBA could visualize the changes of hypochlorite in living zebrafish with the fluorescent change between red and green. Overall, the designed novel probe IBA can serve as a potential tool to analyze hypochlorite and Cu2+, and the exploration of the variations of hypochlorite through living imaging shows potential to study the relevant molecular mechanisms and metabolism routes during multifarious physiological activities.