Used in bioconjugation processes to link biomolecules such as proteins, peptides, or nucleic acids with other functional components via click chemistry. Its long PEG spacer provides flexibility and solubility, reducing steric hindrance in complex biological systems. Commonly applied in drug delivery systems, particularly in antibody-drug conjugates (ADCs) and targeted therapies, where selective and stable coupling is required. Also utilized in surface modification of nanoparticles and medical devices to improve biocompatibility and reduce non-specific binding. The azide group enables efficient copper-catalyzed or strain-promoted azide-alkyne cycloaddition, making it valuable in labeling and imaging applications, including fluorescence tagging for cellular studies.