Used as a redox indicator in analytical chemistry due to its distinct color change with varying oxidation-reduction potential. It is particularly effective in titrations involving strong oxidizing agents, where it shifts from blue to colorless upon reduction. Also employed in photodynamic therapy research owing to its ability to generate reactive oxygen species under light exposure. Its strong electron-donating and light-sensitive properties make it suitable for use in dye-sensitized solar cells and as a photosensitizer in organic synthesis. Additionally, it serves as a fluorescent probe in biochemical assays for detecting electron transfer processes in proteins and enzymes.