Used in bioconjugation and chemical biology as a photoreactive crosslinking agent. Upon exposure to UV light, the azide group generates a nitrene radical that can insert into C–H or N–H bonds, enabling covalent attachment to biomolecules. Commonly employed in probe synthesis for labeling proteins, nucleic acids, or cell surface receptors. Also serves as a building block in click chemistry, particularly in CuAAC or SPAAC reactions, to link fluorophores, affinity tags, or drugs to target molecules. Its benzyl alcohol moiety allows further functionalization or attachment to solid supports. Widely applied in drug discovery, proteomics, and development of diagnostic tools.