Used primarily in bioconjugation and drug delivery systems, it serves as a linker molecule to attach therapeutic agents or targeting moieties to biomolecules. Its structure allows for controlled release of active compounds due to the hydrolyzable ester bond. The PEG (polyethylene glycol) spacer enhances solubility and reduces immunogenicity, making it valuable in developing protein-drug conjugates, antibody-drug conjugates, and other biopharmaceuticals. Additionally, it finds applications in material science for surface modification and functionalization of nanoparticles or polymers.