Bis-PEG11-acid is widely used in the field of bioconjugation and drug delivery due to its ability to act as a linker molecule. Its long polyethylene glycol (PEG) chain enhances solubility and reduces immunogenicity, making it ideal for attaching drugs, proteins, or other biomolecules. In pharmaceutical applications, it is employed to improve the pharmacokinetics and stability of therapeutic agents, ensuring prolonged circulation in the body. Additionally, it is utilized in the development of hydrogels and nanomaterials, where its hydrophilic properties contribute to controlled drug release and biocompatibility. Its versatility also extends to surface modification, where it is used to create non-fouling coatings for medical devices, preventing unwanted protein adsorption and bacterial adhesion.