Sulfo-Cy7 Alkyne is a near-infrared fluorescent dye containing an alkyne functional group, which enables highly selective conjugation to azide-modified biomolecules via copper-catalyzed azide–alkyne cycloaddition (CuAAC). As a sulfonated Cy7 derivative, it emits in the near-infrared window, reducing autofluorescence from biological samples and improving tissue imaging performance. Sulfo-Cy7 alkyne is commonly used for bioorthogonal labeling and in vivo imaging probe construction, with application conditions optimized according to the experimental system.