A super-porous hybrid platform of Pt/CuO/Pt is proposed for the significantly improved electrochemical H 2 O 2 sensor. The proposed hybrid platform demonstrates a superior sensitivity of 16,694 µA mM−1 cm−2 with a limit of detection of 2.91 nM (S/N = 3). [Display omitted] • Demonstration of ultra-sensitive and selective hybrid Pt/CuO/Pt electrode for H 2 O 2 sensing. • Demonstration of ultrahigh sensitivity of 16,694 µA mM−1 with LOD of 2.91 nM. • Demonstration of excellent selectivity against the general interfering molecules. • DFT simulations of CuO, Cu 2 O, Pt and Pd for H 2 O 2 sensing. • Demonstration of a biosensor kit on a single chip, including the working, counter, and reference electrodes. A super-porous Pt/CuO/Pt hybrid electrode is demonstrated with extremely high sensing performance parameters for the hydrogen peroxide (H 2 O 2) detection. A unique physiochemical approach is adapted for the fabrication of 3-D super-porous Pt/CuO/Pt sensing platform. The super-porous Pt/CuO/Pt hybrid platform demonstrates a superior sensitivity of 16,694 µA mM−1 cm−2 with a limit of detection of 2.91 nM (S/N = 3). It also demonstrates an excellent selectivity against the interfering molecules such as NaCl, fructose, ascorbic acid, citric acid, dopamine and glucose with a wide linear range. The demonstrated performance ranks the Pt/CuO/Pt hybrid platform as one of the best H 2 O 2 sensors as summarized in the Table 2. The super-porous CuO layer is fabricated by a dynamic hydrogen bubbling technique of electrochemical deposition and metallic Pt NP decoration is achieved by the physical vapor deposition (PVD) and post-annealing. The super-porous CuO layer offers a drastically improved electrochemical active surface area, and the Pt NP decoration offers a significantly improved conductivity and improved charge accumulation for the H 2 O 2 reduction. The DFT simulations confirm the predominance of CuO over Cu 2 O and Pt over Pd for the H 2 O 2 detection based on the adsorption energy, density of states and charge accumulation calculations. [ABSTRACT FROM AUTHOR]