Used in bioconjugation and chemical synthesis, it serves as a linker molecule to connect biomolecules, such as peptides, proteins, or antibodies, with other functional groups or surfaces. Its PEG (polyethylene glycol) spacer enhances solubility and reduces immunogenicity, making it valuable in drug delivery systems and therapeutic applications. The tosyl group enables efficient coupling reactions, while the terminal carboxylic acid allows for further functionalization or attachment to amine-containing molecules. It is commonly employed in the development of antibody-drug conjugates (ADCs), targeted therapies, and diagnostic probes.