NH-bis(PEG3-azide) is widely used in bioconjugation and click chemistry applications due to its dual azide functional groups and polyethylene glycol (PEG) spacer. The azide groups enable efficient and selective reactions with alkyne-containing molecules via copper-catalyzed azide-alkyne cycloaddition (CuAAC), making it valuable for labeling, crosslinking, and modifying biomolecules such as proteins, peptides, and nucleic acids. The PEG spacer enhances solubility, reduces steric hindrance, and improves biocompatibility, making it suitable for use in drug delivery systems, biophysical studies, and the development of therapeutic conjugates. Additionally, it is employed in materials science for surface functionalization and the creation of advanced polymeric materials. Its versatility and reliability in forming stable triazole linkages make it a key reagent in chemical biology and nanotechnology research.