Used in bioconjugation and drug delivery systems, it serves as a linker molecule to attach therapeutic agents or imaging probes to biomolecules like proteins or peptides. Its PEG (polyethylene glycol) spacer enhances solubility and reduces immunogenicity, while the t-butyl ester group provides stability during synthesis and can be cleaved under specific conditions for controlled release. Commonly applied in the development of antibody-drug conjugates (ADCs) and targeted therapies for cancer treatment. Also utilized in research for modifying peptides to improve their pharmacokinetic properties.