Flavonol-2'-sulfonic Acid Sodium Salt Hydrate is widely used in biochemical research as a fluorescent probe due to its strong fluorescence properties. It is particularly valuable in studying cellular processes, such as tracking molecular interactions and visualizing cellular structures under a microscope. This compound is also employed in the development of sensors for detecting specific ions or molecules in biological samples. Additionally, it finds application in photodynamic therapy, where its light-sensitive properties help in targeting and destroying cancer cells. Its water solubility, enhanced by the sodium salt form, makes it suitable for use in aqueous environments, further expanding its utility in various scientific and medical applications.