Used in bioconjugation for targeted drug delivery and surface modification. The PFP ester group reacts efficiently with primary amines on proteins or peptides, forming stable amide bonds. The disulfide (SS) linker provides a cleavable bond in reducing environments, such as inside cells, enabling controlled release of payloads. The propargyl group allows for click chemistry via copper-catalyzed azide-alkyne cycloaddition (CuAAC), facilitating modular assembly in complex biological systems. Ideal for constructing antibody-drug conjugates (ADCs), functionalizing nanoparticles, and labeling biomolecules with fluorophores or other probes. PEG spacers enhance solubility and reduce non-specific binding, improving bioavailability and performance in biological applications.