Azide-PEG12-Tos is widely used in bioconjugation and click chemistry applications due to its azide functional group, which allows for efficient and selective reactions with alkyne-containing molecules. The polyethylene glycol (PEG) spacer enhances solubility and reduces steric hindrance, making it ideal for modifying biomolecules such as proteins, peptides, and antibodies. The tosyl (Tos) group serves as a reactive handle for further functionalization, enabling the attachment of the compound to thiol or amine groups in target molecules. This makes it a valuable tool in drug delivery systems, surface modification, and the development of bioconjugates for therapeutic and diagnostic purposes. Its versatility and biocompatibility are particularly advantageous in creating stable and functionalized materials for biomedical research.