Used in bioconjugation and targeted drug delivery systems, DSPE-PEG-N3 enables efficient coupling of biomolecules such as peptides, proteins, or fluorescent dyes to liposomes or nanoparticles via click chemistry. The azide (N3) group readily reacts with alkynes under copper catalysis or strain-promoted conditions, allowing site-specific modification without damaging sensitive biological components. Its PEGylated lipid structure enhances the stability and circulation time of nanocarriers in vivo by reducing immune clearance and improving solubility. Commonly applied in developing stealth liposomes for cancer therapy, diagnostic imaging agents, and multifunctional nanoprobes where controlled surface functionalization is required. Also used in surface coating of medical devices and biosensors to immobilize bioactive molecules in a controlled orientation.