Metal oxide intercalated layered double hydroxide nanosphere: With enhanced electrocatalyic activity towards H2O2 for biological applications

Structurally integrated metal oxide intercalated layered double hydroxide (LDH) nanospheres (NSs) hybrid material has been of considerable current interest because of their unique structure and synergistic combination of multi-functional properties of nanocomposites. In this work, we report a new type of MnAl LDH wrapped CuO (CuO@MnAl LDHs) NSs by anchoring CuO nanoparticles (NPs) with MnAl LDHs via a facile co-precipitation and hydrothermal approach, and explore its practical application as high efficient electrocatalyst towards H2O2 reduction for biological application. Our findings demonstrate that the integration of n-type spinel of CuO and p-type semiconductive channels of MnAl LDHs can accelerate electron transfer at breakdown voltage of p-n junction. Owing to the synergistic effect of the high surface area of CuO NPs, superb intercalation features of semiconductive MnAl LDHs for encapsulating NSs, and their intrinsic p-n junction characteristics, CuO@MnAl NSs have exhibited excellent electrocatalytic activity towards the reduction of H2O2. When implemented in electrochemical sensor system, the CuO@MnAl NSs modified electrode displays high nonenzymatic sensing performances towards H2O2 including a broad linear range 6 mu M-22 mM, a low detection limit of 0.126 mu M, good selectivity and long term stability, which can be exploited for in vitro detection of H2O2 in human serum and urine samples, as well as real-time tracking H2O2 secreted from different human live cells. (C) 2016 Elsevier B.V. All rights reserved.