Cu-based metal-organic framework as a novel sensing platform for the enhanced electro-oxidation of nitrite

A stable 3-dimensional (3D) Cu-based metal organic framework (Cu-MOP) was synthesized by a simple solvothermal synthesis and studied with respect to its role in the electro-oxidation of nitrite. As a novel electrode material, the Cu-MOF modified carbon paste electrode (CPE) decreases the oxidation potential of nitrite, which presented a new platform for oxidation of nitrite. It was also found that Cu-MOF exhibited strong absorption property for HAuCl4, and uniform Au microspheres were easily loaded on the surface of the MOF by absorption and electro-reduction (Au/Cu-MOF/CPE). The EDX mapping results showed that Au microspheres were anchored on the surface of Cu-MOF. The resulting Au microspheres accelerated the electron transfer rate of electrochemical reaction, and further decreased the oxidation potential of nitrite. The prepared Au/Cu-MOF/CPE demonstrated low detection limit, wide linear range, and good stability for the determination of nitrite. The results indicated that Cu-MOF would be a promising material to construct novel electrochemical sensor. (C) 2015 Elsevier B.V. All rights reserved.