This chemical is widely used in bioconjugation and click chemistry applications due to its azido and carboxyl functional groups. The azide group allows for efficient and selective reactions with alkynes via copper-catalyzed azide-alkyne cycloaddition (CuAAC), making it valuable for labeling biomolecules such as proteins, peptides, and nucleic acids. The presence of multiple carboxyl groups enables further modification or attachment to amine-containing molecules through amide bond formation, enhancing its versatility in creating complex molecular architectures. Additionally, the PEG4 spacer provides hydrophilicity and flexibility, improving solubility and reducing steric hindrance in biological systems. It is particularly useful in drug delivery, surface functionalization, and the development of bioconjugated probes for imaging and diagnostic purposes.