This study explores the synthesis and characterization of europium-doped silver selenide (Eu-AgSe) nanoparticles along with their application in electrochemical studies. The nanoparticles are synthesized a hydrothermal method using silver, selenide and europium as precursors in the environment of octylamine solution. Comprehensive structural, morphological, and functional analyses are performed using X-ray diffraction (XRD), field-effect scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), and Fourier transform infrared spectroscopy (FTIR). Electrochemical performance , in supercapacitors and glucose sensors, is assessed through electrochemical experiments like cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS). It has been observed that Europium doping significantly enhanced the specific capacitance, achieving 337.8 F g at a current density of 0.14 A g, with an energy density of 8.4 W h kg and a power density of 29.9 W kg. Additionally, the materials exhibited excellent cyclic stability, retaining 93% of their initial capacitance after 6000 cycles. Similarly, the sensitivity of the Eu-AgSe nanoparticles is calculated as 0.52 μA μMcm in the linear range having good stability, selectivity and reproducibility. These results highlight the potential of Eu-AgSe nanoparticles as a promising candidate for next-generation energy storage systems and glucose sensing applications.