Used in bioconjugation for drug delivery and protein modification due to its ability to link molecules via thiol-reactive chemistry. The SS (disulfide) linker provides cleavability under reducing conditions, making it ideal for intracellular delivery systems. PEG3 spacer enhances solubility and reduces aggregation, while the Boc-protected amine allows for controlled deprotection and further coupling reactions. Commonly applied in the development of antibody-drug conjugates (ADCs), targeted therapies, and functionalized nanoparticles.