Azido-PEG1-C2-acid is widely used in bioconjugation and click chemistry applications, particularly in the modification of biomolecules such as proteins, peptides, and nucleic acids. Its azide group enables efficient and selective reactions with alkyne-functionalized compounds via copper-catalyzed azide-alkyne cycloaddition (CuAAC), making it a valuable tool for creating stable triazole linkages. This compound is also employed in the development of drug delivery systems, where it facilitates the attachment of targeting ligands or therapeutic agents to carrier molecules. Additionally, it is utilized in surface functionalization for materials science, enabling the modification of nanoparticles, polymers, and other substrates for enhanced biocompatibility or specific interactions. Its PEG spacer improves solubility and reduces steric hindrance, making it suitable for applications in biomedical research and diagnostics.