This compound is widely used in bioconjugation chemistry due to its reactive NHS ester group, which enables efficient coupling with primary amines in proteins, peptides, or other biomolecules. The azide group allows for further functionalization via click chemistry, particularly copper-catalyzed azide-alkyne cycloaddition (CuAAC), making it valuable for labeling, crosslinking, or modifying biomolecules. It is commonly applied in the development of drug delivery systems, where it helps attach targeting ligands or therapeutic agents to carriers. Additionally, it plays a role in surface modification, enabling the immobilization of biomolecules onto substrates for biosensors or diagnostic assays. Its PEG spacer enhances solubility and reduces steric hindrance, improving the efficiency of bioconjugation reactions.