4-Nitro-1,8-naphthalic anhydride serves as a key intermediate in the synthesis of fluorescent naphthalimide derivatives, which exhibit strong emission under UV light. These derivatives are used as probes in bioimaging, selectively binding to proteins and cellular membranes to visualize cellular structures in live and fixed cells. The compound is also utilized in developing chemosensors for detecting metal ions like zinc and copper in environmental and biological samples. The high photostability of the resulting naphthalimides makes them ideal for long-term fluorescence tracking in microscopy. Furthermore, it functions as a building block for synthesizing dyes and optoelectronic materials.