This work reports a coordination polymer-derived nanosized Zn_0.6Mn_2.4O₄ as the electrode material for supercapacitor and sensing material for nitroaromatics in an aqueous medium. A bimetallic coordination polymer of formula {(H₂pip)₃[Zn_xMn_(3–x)(pydc-2,5)₆(H₂O)₃]·6H₂O} {where x = 0.6}, 1, was prepared through a hydrothermal process and utilized as a template. The structural information and phase information of 1 were examined by comparing the PXRD pattern of the compound with that of the pure Mn-based compound, 1a, simulated from the single-crystal X-ray data. Zn_0.6Mn_2.4O₄ nanoparticles were synthesized by calcining the bimetallic coordination polymer, 1, at 350 °C for 1 h. The as-obtained Zn_0.6Mn_2.4O₄ nanoparticles were thoroughly identified using PXRD, TEM, and EDX analyses. Scherrer’s formula gives the average particle size of about 25 nm for Zn_0.6Mn_2.4O₄. Nanostructured Zn_0.6Mn_2.4O₄ was operated as a pseudocapacitor electrode in 2 M KOH solution, which shows a specific capacitance of 1334 F g^–1 at a scan rate of 5 mV s^–1 in a three-electrode cell configuration. CV study exhibits long-term cycling performance with 90.5% retention of its original capacitance after 1500 cycles. On the other hand, upon excitation at 295 nm, the aqueous dispersion of nanosized Zn_0.6Mn_2.4O₄ displays a strong emission peak centered at 410 nm and was utilized to trace a very low concentration of nitroaromatics in the water medium. Among the nitroaromatics, the addition of 50 μM of TNP quenches around 90% of the luminescence intensity of the aqueous suspended Zn_0.6Mn_2.4O₄. The observed detection limit for TNP is 70 ppb. This outstanding sensitivity of Zn_0.6Mn_2.4O₄ nanoparticles toward nitroaromatics inspired us to use it as a nitroaromatics detector. These results demonstrate that the nanostructured Zn_0.6Mn_2.4O₄ could be a potential supercapacitor as well as a nitroaromatics detector with striking sensitivity for commercial purposes.