Fabrication of carbon nanotube-nickel nanoparticle hybrid paste electrodes for electrochemical sensing of carbohydrates

Carbon nanotube-nickel nanoparticle (CNT-NiNP) hybrid was prepared by the chemical reduction of a mixture containing nickel sulfate and CNTs using hydrazine. The structure of the material was characterized by scanning electron microscopy, energy dispersive spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and vibrating sample magnetometery. A mixture of the CNT-NiNP hybrid and paraffin oil was packed into fused capillaries to fabricate paste electrodes for electrochemical sensing. The performance of the fabricated electrodes was demonstrated by measuring four carbohydrates in combination with cyclic voltammetry and capillary electrophoresis. The advantages of the electrodes include higher sensitivity, satisfactory stability, surface renewability, and low expense of fabrication. They may find wide applications in microchip capillary electrophoresis, flowing-injection analysis, and other microfluidic analysis systems.