NBD-undecanoic acid, a multifunctional dye, serves as an essential tool in various biological experiments. It enables researchers to observe and analyze cell structures, track biomolecules, and evaluate cell functions. Additionally, this dye aids in distinguishing cell types, detecting biomolecules, studying tissue pathology, and monitoring microorganisms. Its applications are extensive, encompassing not only basic scientific research and clinical diagnostics but also traditional sectors like textile dyeing. Moreover, NBD-undecanoic acid finds use in emerging areas including functional textile processing, food pigments, and dye-sensitized solar cells.