Used in bioconjugation processes, particularly in click chemistry applications. The azide group enables copper-catalyzed azide-alkyne cycloaddition (CuAAC) reactions, allowing efficient and selective attachment to biomolecules such as peptides, proteins, or nucleic acids. The disulfide (SS) linker provides a reducible bond, useful for intracellular delivery systems where the bond is cleaved in the reducing environment of the cytoplasm. Commonly employed in the development of antibody-drug conjugates (ADCs), targeted therapies, and diagnostic probes where controlled release or modular assembly is required. Its carboxylic acid functionality allows further activation and coupling to amines, making it a versatile bifunctional crosslinker in bioconjugate chemistry.