Simultaneous Discrimination of Hypochlorite and Single Oxygen during Sepsis by a Dual-Functional Fluorescent Probe

Hypochlorite (ClO^-) and singlet oxygen (¹O₂) commonly coexist in living systems and exert important interplaying roles in many diseases. To dissect their complex inter-relationship, it is urgently required to construct a fluorescent probe that can discriminate ClO^- and ¹O₂ in living organisms. Herein, by taking the 3-(aliphaticthio)-propan-1-one group as the unique recognition unit for both ClO^- and ¹O₂, we proposed the first fluorescent probe, Hy-2, to simultaneously discriminate ClO^- and ¹O₂ with high sensitivity and selectivity. Probe Hy-2 itself showed fluorescence in blue channel. After treatment with ClO^- and ¹O₂, respectively, pronounced fluorescence enhancements were observed in the green channel and red channel correspondingly. Moreover, upon development of the probe with aggregation-induced emission (AIE) characteristics, the probe could work well in a solution with high water volume fraction. Probe Hy-2 was also able to accumulate into mitochondria and was utilized as an effective tool to image exogenous and endogenous ClO^- and ¹O₂ in mitochondria. Significantly, as the first trial, probe Hy-2 was employed to simultaneously monitor the variation of ClO^- and ¹O₂ level in cecal tissues of rat in the cecal ligation and puncture (CLP)-induced polymicrobial sepsis model. The results demonstrated that the expressed ClO^- and ¹O₂ levels were tightly correlated with the severity of sepsis, inferring that the overproduction of ClO^- and ¹O₂ is an important factor in the pathogenesis of sepsis. The probe illustrated herein may provide a guide for further exploring the functions of ClO^- and ¹O₂ in various diseases.