This chemical is widely used in bioconjugation and click chemistry applications. Its azide group enables efficient and selective reactions with alkyne-containing molecules, making it valuable for labeling biomolecules such as proteins, peptides, and nucleic acids. The PEG (polyethylene glycol) spacers enhance solubility and reduce steric hindrance, improving reaction efficiency. Additionally, the presence of PEG4-acid groups allows for further functionalization or attachment to surfaces, making it suitable for drug delivery systems, diagnostic assays, and material science research. Its versatility and biocompatibility make it a key reagent in the development of targeted therapeutics and advanced biomaterials.