An amperometric glucose biosensor based on the immobilization of glucose oxidase on the platinum electrode modified with NiO doped ZnO nanorods

A novel glucose biosensor was fabricated by immobilizing glucose oxidase (GOD) on a platinum electrode modified with NiO doped ZnO nanorods (NRs), which were adopted to construct an amperometric glucose biosensor for the first time. ZnO single-crystalline nanorod and NiO doped ZnO nanorods are prepared by hydrothermal method and characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The electrochemical behavior of the platinum electrode modified with NiO doped ZnO nanorod was investigated in phosphate buffer solution (PBS). The effect of molar ratio of Ni/Zn in the doped ZnO nanorod, pH value, applied potential, temperature was investigated in detail. Under the optimal experimental condition, the constructed glucose biosensor showed a good linearly relationship between the concentration of glucose and the electrochemical current, a high sensitivity of 61.78 μA/mM cm2, and a fast response time of <5 s. All results demonstrate that the NiO doped ZnO NRs can provide a new platform for glucose biosensor design and other biological applications.