This chemical is primarily used in bioconjugation and labeling applications, particularly in the development of biopharmaceuticals and research tools. Its structure, featuring a propargyl group and a PEG spacer, makes it highly suitable for click chemistry reactions, such as the copper-catalyzed azide-alkyne cycloaddition (CuAAC). This enables efficient and specific attachment of molecules like proteins, peptides, or antibodies to other functional groups, such as azides, for targeted drug delivery, imaging, or diagnostic purposes. The PEG spacer enhances solubility and reduces steric hindrance, improving the performance of the conjugate in biological systems. Additionally, its acid group allows for further functionalization or coupling to amine-containing molecules, expanding its utility in creating complex biomolecular constructs.