Used extensively in bioconjugation and chemical biology, this compound serves as a versatile linker for attaching molecules to proteins, peptides, or other biomolecules. Its azido group enables click chemistry reactions, particularly with alkynes, allowing for efficient and selective coupling. The PEG4 spacer enhances solubility and reduces steric hindrance, making it ideal for creating stable conjugates in drug delivery systems, diagnostic probes, and functionalized nanomaterials. Additionally, its hydroxyl group provides a site for further modification, expanding its utility in designing complex molecular architectures for research and therapeutic applications.