Electrochemical Sensors for Simultaneous Determination of Small Biomolecules By 3D Layered Hollow Honeycomb-like Ni-NiO@CPVP Modified Glassy Carbon Electrode

A novel method for preparation of hybrid material of nickel and nickel oxide (Ni-NiO) nanoparticles doping at the three-dimensional (3D) honeycomb-like surface of carbonated polyvinylpyrrolidone K30 (CPVP) via a one-pot, co-pyrolysis strategy was developed. The morphology and composition of Ni-NiO@CPVP nanocomposite were well characterized by microscopy and spectroscopy, indicating its high specific surface area with the loading of catalytic Ni. These features enable large electrochemically active surface area, rapid electron transfer, especially facilitate the discrimination of analytes which oxidize or reduce at similar potentials. After fixation of Ni-NiO@CPVP composite, the modified electrode exhibited excellent sensing ability towards dopamine (DA), ascorbic acid (AA) and uric acid (UA). Broad liner ranges (5.0–4200 μmol/L, 0.05–75 μmol/L and 0.2–120 μmol/L) and low limits of detection (LODs) (1.0, 0.03 and 0.05 μmol/L) were achieved for AA, DA and UA, respectively. Moreover, this sensor offered a good opportunity for simultaneous profiling of AA, DA and UA with excellent reproducibility, repeatability and long-term stability. The good performance for the measurement of real samples indicated the promising future of this sensor. Finally, the possible sensing mechanism was proposed.