Aminooxy-PEG1-propargyl is widely used in bioconjugation and chemical biology for attaching molecules to biomolecules such as proteins, peptides, or antibodies. Its aminooxy group reacts selectively with aldehydes or ketones to form stable oxime bonds, enabling the modification of biomolecules under mild conditions. The propargyl group allows for further functionalization via click chemistry, particularly copper-catalyzed azide-alkyne cycloaddition (CuAAC), making it a versatile linker in the development of drug delivery systems, diagnostic probes, and bioconjugates. It is also employed in the synthesis of PEGylated compounds to improve solubility, stability, and pharmacokinetic properties of therapeutic agents.