Used as a fluorescent probe in biological imaging due to its strong emission properties and sensitivity to the local environment. It is incorporated into sensors for detecting reactive oxygen species and other biologically relevant molecules. Also applied in materials science for developing organic semiconductors and optoelectronic devices because of its electron-accepting character and stability in conjugated systems. Its selenium-containing structure enhances spin-orbit coupling, making it useful in photodynamic therapy research and triplet photosensitizers.