Used in bioconjugation and labeling applications, particularly in the modification of biomolecules such as proteins, peptides, and antibodies. The PEG4 spacer enhances solubility and reduces steric hindrance, making it suitable for efficient coupling reactions. The PFP ester group is highly reactive with amines, enabling stable amide bond formation. This compound is valuable in drug delivery systems, diagnostic assays, and the development of targeted therapies, where precise attachment of functional groups is essential. Its versatility also extends to materials science for surface functionalization and polymer modification.