This compound is widely used in bioconjugation and labeling applications due to its reactive NHS ester group, which facilitates efficient coupling with primary amines in proteins, peptides, or other biomolecules. The azide group enables click chemistry reactions, particularly copper-catalyzed azide-alkyne cycloaddition (CuAAC), making it valuable for attaching fluorescent dyes, drugs, or other functional groups to biomolecules. Its PEG spacer enhances solubility and reduces steric hindrance, improving reaction efficiency. It is commonly employed in drug delivery systems, biophysical studies, and the development of diagnostic probes.