Porous ZnO and ZnO-NiO composite nano/microspheres: synthesis, catalytic and biosensor properties

Porous ZnO and ZnO-NiO composite nano/microspheres have been successfully synthesized by the calcination of non-doped and Ni(II)-doped precursors in air, respectively. The catalytic effect was investigated for porous ZnO and ZnO-NiO composite nano/microspheres for the thermal decomposition of ammonium perchlorate (AP). The ZnO-NiO composite nano/microspheres showed remarkable catalytic effect for the thermal decomposition of AP. The decomposition temperature was decreased by 144.5 degrees C, and the apparent activation energy was significantly decreased to 117.8 kJ mol(-1), which is considerably lower than 159.7 kJ mol(-1) for pure AP. The catalytic capacity of ZnO-NiO composite nanostructures is higher than that of most of the materials reported to date. As a result, porous ZnO-NiO composite nano/microstructures could be a promising candidate material for an AP-based propellant. In addition, using the as-prepared porous ZnO microspheres, we have successfully prepared a novel, ultrahigh resolution electrochemical impedance DNA biosensor for the enhanced detection of the PML/RARA fusion gene in acute promyelocytic leukemia with a detection limit of 2.2 x 10(-13) mol L-1; therefore, it can act as a biosensing materials for the recognition of DNA hybridization.