Used as a photoaffinity labeling agent in biochemical research to study receptor binding sites and enzyme active sites. Upon exposure to UV light, the azido group generates a reactive nitrene species that forms covalent bonds with nearby biomolecules, allowing identification and mapping of molecular interactions. Particularly useful in probing neurotransmitter receptors and other protein targets due to its ability to mimic structural features of biologically active compounds. Also employed in the development of chemical probes and in click chemistry applications when combined with alkyne-functionalized tags.