Visualizing detection of cysteine level under LPS-induced oxidative stress process using benzopyrylium-based mitochondrial-targeted NIR fluorescent probe

Abstract

As an important scavenger of reactive oxygen species, cysteine (Cys) plays a crucial role in mitochondrial oxidative stress. Abnormal intracellular Cys concentration under oxidative stress leads to various diseases. Cys is also widely used in the food industry. Many vegetables and fruits are rich in Cys. Abnormal levels of Cys in the body can lead to a variety of diseases. Therefore, the design of fluorescent probe that can detect Cys quickly is particularly important in living organisms. In this work, a novel turn-on mitochondrial-targeted NIR fluorescent probe (SXNU-6) was designed for the high sensitivity and specificity of Cys based on benzopyrylium. Among them, acrylate group acted as recognition site and fluorescence quencher. With the addition of Cys, the fluorescence of SXNU-6 was gradually enhanced at 660 nm. The probe had good selectivity and high sensitivity, which could realize the detection of Cys in food samples (onion, garlic, tomato, lettuce, apple, pear, milk and bread). Also, SXNU-6 could detect both endogenous and exogenous Cys under LPS-induced oxidative stress process. This work provide a powerful tool for detecting Cys in food samples and biological systems.