Used primarily in bioconjugation, it serves as a linker to attach biomolecules like proteins, peptides, or antibodies to other molecules or surfaces. Its NHS ester group reacts with amine groups, enabling stable amide bond formation, while the PEG spacer enhances solubility and reduces steric hindrance. Commonly applied in drug delivery systems to improve the pharmacokinetics of therapeutic agents. It is also utilized in diagnostic assays for labeling and detection purposes. Additionally, it plays a role in surface modification to create biocompatible materials for medical devices.