N-(4-Nitrophenyl)maleimide is widely used in organic synthesis as a building block for creating complex molecules. Its maleimide group reacts with thiols, making it useful for forming thioether linkages in peptides and proteins. In polymer chemistry, it acts as a crosslinking agent to improve the mechanical and thermal properties of polymers. It is also employed in bioconjugation to attach labels or functional groups to biomolecules for biochemical assays and diagnostics. In material science, it introduces nitro groups into polymers or other materials for use in sensors or coatings. Additionally, it serves as a reagent in research studies to investigate reaction mechanisms involving maleimide and nitro group chemistry.