Dual-Site Fluorescent Sensor as a Multiple Logic System for Studying the Dichotomous Function of Sulfur Dioxide under Oxidative Stress Induced by Peroxynitrite

Abstract

Intracellular reactive oxygen species and reactive sulfur play a vital role in regulating redox homeostasis and maintaining cell functions. Sulfur dioxide (SO₂) has emerged as an important gas signal molecule recently, which is not only a potential reducing agent but also a potential inductor of oxidative stress in organisms. Due to high reactivity, peroxynitrite (ONOO^-) could act on many biomolecules, such as proteins, lipids, and nucleic acids, and cause irreversible damage, eventually leading to cell apoptosis or necrosis. In order to further illuminate the dichotomous role of SO₂ under oxidative stress induced by ONOO^-, we designed the first dual-site fluorescent sensor (<b>NIR-GYf</b>) for separate or continuous detection of SO₂ and ONOO^-. <b>NIR-GYf</b> was successfully used for cell imaging of endogenous SO₂ and ONOO^-. In addition, western blotting analysis was used to verify the oxidation and antioxidation of SO₂ and its dichotomous biological influence. Finally, <b>NIR-GYf</b> was integrated with multiple Boolean logic operations to construct an advanced analysis device, thereby realizing the direct analysis of SO₂ and ONOO^- levels.