Used primarily as a fluorescent dye in biological imaging and research. It is effective in labeling and tracking cellular components due to its strong absorption and emission in the near-infrared region. This makes it suitable for deep tissue imaging, as near-infrared light penetrates tissues more effectively. It is also utilized in photodynamic therapy, where it helps in targeting and destroying cancer cells when activated by specific light wavelengths. Additionally, it serves as a sensitizer in photographic emulsions and in the development of optical storage media.