Among the analytical methods for measuring small amounts of metal ions, potentiometric ion-selective sensors have high speed, precision, and accuracy and are more convenient to use. On the other hand, one-pot synthesis offers an attractive and sustainable approach by reducing waste, saving time, and simplifying complex multi-step reactions. Another important advantage of one-pot synthesis lies in its improved atom economy and reduced environmental footprint. In this research, a new Ba²⁺ ion-extracting potentiometric sensor based on 1,2-bis(4-nitrophenyl) ethane-1,2-dione (4,4’-dinitrobenzil) (BNED) ligand was prepared. The interaction between the ligand with barium ions and other metal ions were investigated through UV-Vis spectroscopy, which indicated the selectivity for Ba²⁺. The optimal percentage composition for the present electrode membrane is 37:55:3:5, respectively for PVC:BA: NaTPB: BNED. This sensor has a Nernst slope of 24.9 mV/Decade in the linear range of 1-10^-7 M to 1-10^-2 M. The response of the electrode in the pH range of 4.0 to 10.5 is independent of the changes in the concentration of H⁺ ions. The designed electrode has a lifespan of about 3 months and a response time of about 25 seconds. This sensor has good selectivity for Ba²⁺ over various cations (alkali metals, alkaline earth metals, heavy metals and transition metals). The electrode prepared in the present study was used as a detector electrode in the measurement of Ba²⁺ in real samples.