Used extensively in bioconjugation and protein modification processes, it serves as a linker to attach functional groups or biomolecules. Its PEG (polyethylene glycol) spacer enhances solubility and reduces immunogenicity, making it valuable in drug delivery systems. The tert-butyl ester group provides stability during synthesis and can be easily deprotected to expose reactive sites for further chemical reactions. Commonly applied in the development of antibody-drug conjugates (ADCs) and targeted therapeutics, it improves the pharmacokinetic properties of drugs. Additionally, it is utilized in the creation of bioprobes and diagnostic tools for studying biological interactions.