Used in bioorthogonal chemistry for labeling biomolecules in living systems without interfering with natural biochemical processes. Its strain-promoted azide-alkyne cycloaddition enables fast and selective conjugation with azide-containing molecules, making it ideal for imaging, drug delivery, and protein modification. Commonly applied in live-cell labeling, tracking metabolic pathways, and developing targeted therapeutics due to its fast reaction kinetics and no need for toxic catalysts. Also utilized in materials science for surface functionalization and creating bioconjugates in complex environments.