4-Nitrocinnamic acid is widely used in organic synthesis, particularly as a building block for more complex molecules. It serves as a key intermediate in the preparation of pharmaceuticals, agrochemicals, and dyes. Its nitro group and conjugated double bond make it a valuable component in photochemical reactions, often utilized in the study of light-induced processes. Additionally, it is employed in material science for the development of nonlinear optical materials due to its ability to enhance optical properties. In biochemistry, it is used as a substrate in enzymatic studies to investigate reaction mechanisms and enzyme kinetics. Its versatility also extends to the field of polymer chemistry, where it aids in the synthesis of functionalized polymers with specific properties.