Super-porous Pt/CuO/Pt hybrid platform for ultra-sensitive and selective H2O2 detection

A super-porous Pt/CuO/Pt hybrid electrode is demonstrated with extremely high sensing performance parameters for the hydrogen peroxide (H2O2) 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 mu A 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 H2O2 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 H2O2 reduction. The DFT simulations confirm the predominance of CuO over Cu2O and Pt over Pd for the H2O2 detection based on the adsorption energy, density of states and charge accumulation calculations.