This chemical, Fmoc-NH-PEG5-C2-NH2, is widely used in peptide synthesis, particularly in solid-phase peptide synthesis (SPPS), as a protecting group for amines, ensuring selective reactions during the formation of peptide bonds. Its polyethylene glycol (PEG5) spacer enhances solubility in aqueous solutions, making it suitable for bioconjugation and drug delivery applications. It is particularly useful in the development of peptide-based therapeutics, where it helps improve stability and bioavailability. Additionally, it is employed in the preparation of functionalized materials for biosensors and diagnostic tools, where its terminal amine group allows for precise attachment to target molecules via standard coupling chemistries. Its versatility also extends to the field of nanotechnology, where it aids in the surface modification of nanoparticles for targeted drug delivery systems.