Cu(II)-Based MOF Immobilized on Multiwalled Carbon Nanotubes: Synthesis and Application for Nonenzymatic Detection of Hydrogen Peroxide with High Sensitivity

Cu(II)-based MOF (Cu-bipy-BTC, bipy= 2,2'-bipyridine, BTC=1,3,5-tricarboxylate) was synthesized and immobilized on multiwalled carbon nanotubes. The prepared composite was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectra (XPS) and IR spectra. Then the material was modified onto the surface of a glassy carbon electrode, and showed a couple of well-defined redox peaks in a phosphate buffer solution (pH 6.0), ascribed to the redox process of Cu-II/I in the Cu-bipy-BTC. The modified electrode was then applied to fabricate a non-enzymatic hydrogen peroxide biosensor. The sensor showed good electrocatalytic activity toward the reduction of hydrogen peroxide with a wide linear range (3-70 mu mol L-1 and 70-30000 mu mol L-1) and a detection limit of 0.46 mu mol L-1, as well as good stability and repeatability. In addition, the sensor has been successfully applied to determine hydrogen peroxide in water samples with good accuracy. Thus, the Cu-bipy-BTC/MWCNTs composite has great potential for applications in electrochemical sensors.