This compound is widely used in bioconjugation and chemical biology for attaching polyethylene glycol (PEG) chains to biomolecules like proteins, peptides, and antibodies. The NHS ester group allows for efficient coupling with primary amines, while the propargyl group enables further modification through click chemistry, such as azide-alkyne cycloaddition. This makes it valuable in drug delivery systems, where PEGylation enhances solubility, stability, and circulation time of therapeutic agents. It is also employed in the development of biosensors, diagnostics, and targeted therapies, where precise and stable conjugation is essential. Additionally, it finds applications in surface functionalization of materials for biomedical research.