2-Nitrophenyl octyl ether (NPOE) is primarily used as a non-polar solvent mediator and plasticizer in the preparation of polymeric membranes for ion-selective electrodes (ISEs), especially potassium-selective electrodes. It enhances the ionophoric properties and stability of PVC-based sensing membranes, enabling selective detection of metal ions such as K⁺. The nitroaromatic moiety provides electron-withdrawing characteristics, making it suitable as a key intermediate in organic synthesis for fluorescent probes, chemosensors targeting metal ions and anions, photochemical applications, and nonlinear optical materials. It is also utilized in the formulation of specialty dyes and as a stabilizer in analytical systems.