Tos-PEG9-Tos is widely used in bioconjugation and chemical synthesis due to its bifunctional nature. The tosyl groups at both ends of the PEG chain allow for efficient attachment to various molecules, making it a valuable linker in the development of drug delivery systems. It is particularly useful in creating PEGylated compounds, which enhance the solubility, stability, and bioavailability of therapeutic agents. Additionally, it finds applications in modifying surfaces and biomaterials to improve their biocompatibility and performance in medical devices. Its role in crosslinking and functionalizing polymers also makes it important in material science and nanotechnology research.