N-(Azido-PEG3)-N-(PEG2-amine)-PEG3-acid is widely used in bioconjugation and drug delivery applications due to its unique structure. The azide group enables click chemistry reactions, particularly copper-catalyzed azide-alkyne cycloaddition (CuAAC), allowing for efficient and selective attachment to biomolecules or surfaces. The PEG chains enhance solubility, reduce immunogenicity, and improve biocompatibility, making it ideal for modifying proteins, peptides, or nanoparticles. The amine group provides a reactive site for further functionalization, while the carboxylic acid group allows for conjugation with amine-containing molecules via amide bond formation. This compound is particularly valuable in targeted drug delivery systems, where it facilitates the attachment of therapeutic agents to targeting moieties. It is also used in the development of hydrogels, biosensors, and diagnostic tools, where precise molecular assembly and biocompatibility are critical.