This chemical is widely used in bioconjugation and drug delivery systems due to its polyethylene glycol (PEG) spacer, which enhances solubility and reduces immunogenicity. It serves as a linker in the synthesis of antibody-drug conjugates (ADCs), enabling the attachment of therapeutic agents to antibodies for targeted cancer therapy. Additionally, it is employed in the modification of peptides and proteins to improve their stability and prolong their circulation time in the body. The carboxylic acid group allows for further functionalization, making it a versatile tool in the development of biopharmaceuticals and nanomaterials.