4-Nitro-m-phenylenediamine serves as a multifunctional dye, playing a crucial role in biological experiments. These dyes assist researchers in observing and analyzing cellular structures, tracking biomolecules, evaluating cellular functions, differentiating cell types, detecting biomolecules, studying tissue pathology, and monitoring microorganisms. Their applications span from basic scientific research to diverse clinical diagnostics. Additionally, dyes are extensively used in traditional textile dyeing, as well as in innovative areas such as functional textile processing, food pigmentation, and dye-sensitized solar cells.