Used in bioconjugation for labeling and immobilizing biomolecules due to its DBCO group, which undergoes strain-promoted azide-alkyne cycloaddition (SPAAC) without copper catalyst. This enables efficient and selective coupling with azide-containing molecules in live cells or sensitive biological systems. The terminal carboxylic acid allows further activation and attachment to amines on proteins, peptides, or surfaces. The amine group in the middle spacer can be used for additional modifications, such as fluorescent dye labeling or crosslinking. Commonly applied in drug delivery systems, diagnostic probes, and surface functionalization in biosensors. The hydrophilic linker improves solubility and reduces aggregation in aqueous environments.