Phenol-amido-C1-PEG3-N3 is widely used in bioconjugation and chemical biology due to its versatile functional groups. The phenol group allows for specific modifications, while the azide (N3) enables click chemistry reactions, particularly copper-catalyzed azide-alkyne cycloaddition (CuAAC), for labeling biomolecules. The PEG3 spacer enhances solubility and reduces steric hindrance, making it ideal for attaching molecules to proteins, peptides, or other biomolecules without disrupting their function. It is commonly employed in drug delivery systems, antibody-drug conjugates, and the development of diagnostic probes. Additionally, its structure facilitates the study of protein interactions and cellular processes in research applications.