Mal-PEG1-PFP ester is widely used in bioconjugation chemistry, particularly for linking biomolecules such as peptides, proteins, or antibodies to other functional groups or surfaces. Its PFP (pentafluorophenyl) ester group reacts efficiently with amines, enabling the formation of stable amide bonds, while the maleimide (Mal) group selectively reacts with thiols, making it ideal for targeting cysteine residues in proteins. This dual functionality allows for precise and controlled modifications, often employed in the development of antibody-drug conjugates (ADCs) or targeted drug delivery systems. Additionally, it is utilized in surface functionalization for biosensors and nanomaterials, enhancing their specificity and performance in biomedical applications.