M-Peg5-phosphonic acid is widely used in bioconjugation and surface modification due to its ability to introduce hydrophilic and biocompatible properties. It is often employed in the development of drug delivery systems, where it enhances the solubility and stability of therapeutic agents. In material science, it is utilized to modify surfaces of nanoparticles or biomaterials, improving their compatibility with biological systems and reducing nonspecific interactions. Additionally, it plays a role in the synthesis of functionalized polymers and coatings, contributing to the creation of antifouling or bioactive surfaces. Its phosphonic acid group allows for strong binding to metal oxides, making it valuable in applications like sensor development and catalysis.