Used in bioconjugation for site-specific labeling of biomolecules due to its strain-promoted alkyne functionality, enabling copper-free click chemistry with azides. The PEG3 spacer enhances solubility and reduces aggregation, making it ideal for modifying peptides, proteins, and antibodies in live-cell imaging and drug delivery systems. The Boc-amine group allows for controlled deprotection and further coupling reactions, facilitating stepwise synthesis in complex molecular architectures. Commonly applied in developing biotherapeutics, diagnostics, and functionalized surfaces where minimal nonspecific binding and high stability are required.