This compound is widely used in bioconjugation chemistry, where it serves as a linker to attach various molecules, such as drugs or imaging agents, to proteins, peptides, or other biomolecules. Its acid group allows for covalent bonding with amine-containing compounds, while the PEG (polyethylene glycol) spacer enhances solubility and reduces immunogenicity. It is particularly valuable in drug delivery systems, where it helps improve the stability and bioavailability of therapeutic agents. Additionally, it is employed in the development of antibody-drug conjugates (ADCs) and other targeted therapies, enabling precise delivery of active agents to specific cells or tissues. Its ester group can also be hydrolyzed under certain conditions, offering controlled release of the attached molecule.