Dual-Site Fluorescent Sensor as a Multiple Logic System forStudying the Dichotomous Function of Sulfur Dioxide underOxidative Stress Induced by Peroxynitrite

:intracellular reactive oxygen species and reactive sulfur play a vital role inregulating redox homeostasis and maintaining cell functions. Sulfur dioxide (SO2) hasemerged as an important gas signal molecule recently, which is not only a potentialreducing agent but also a potential inductor of oxidative stress in organisms. Due to highreactivity, peroxynitrite (ONOO-) could act on many biomolecules, such as proteins,lipids, and nucleic acids, and cause irreversible damage, eventually leading to cellapoptosis or necrosis. In order to further illuminate the dichotomous role of SO2underoxidative stress induced by ONOO-, we designed thefirst dual-sitefluorescent sensor(NIR-GYf) for separate or continuous detection of SO2and ONOO-.NIR-GYfwassuccessfully used for cell imaging of endogenous SO2and ONOO-. In addition, westernblotting analysis was used to verify the oxidation and antioxidation of SO2and itsdichotomous biological influence. Finally,NIR-GYfwas integrated with multipleBoolean logic operations to construct an advanced analysis device, thereby realizing thedirect analysis of SO2and ONOO-levels

Automated summary

Intracellular reactive oxygen species and reactive sulfur play important roles in redox homeostasis. SO2 has emerged as a vital gas signal molecule with potential reducing and oxidative stress-inducing properties. This study designed the first dual-site fluorescent sensor NIR-GYf for the separate or continuous detection of SO2 and ONOO-. The sensor successfully imaged endogenous SO2 and ONOO- in cells. Western blotting analysis confirmed the oxidation and antioxidation of SO2 and its dual biological influence. NIR-GYf was further integrated with multiple Boolean logic operations to enable direct analysis of SO2 and ONOO- levels.