Used in bioconjugation reactions, particularly in click chemistry, to modify biomolecules such as peptides, proteins, and nucleic acids. Its azide group reacts efficiently with alkynes via copper-catalyzed azide-alkyne cycloaddition (CuAAC), enabling site-specific labeling and attachment to surfaces or functional tags. The PEG6 spacer enhances solubility in aqueous and organic media, reduces aggregation, and minimizes steric hindrance, improving reaction efficiency and biocompatibility. Commonly applied in drug delivery systems, diagnostic probes, and the development of bioconjugate therapeutics where controlled linkage and improved pharmacokinetics are required.