ZnO@C Microballs Wrapped with Ni(OH)₂ Nanofilms for Electrochemical Sensing of Glucose and Hydrogen Peroxide

Tailor-made metal oxide/hydroxide core-shell structures are promising for the fabrication of effective electrocatalysts. Here, we report the development of a core-shell structure based on carbon-doped and Ni(OH)₂ nanofilms wrapped ZnO microballs (NFs-Ni(OH)₂ /ZnO@C MBs) for glucose and hydrogen peroxide (H₂ O₂ ) monitoring. The unique ball-like morphology of the designed structure is achieved through a facile solvothermal strategy by the control of reaction conditions. Typically, ZnO@C MBs offer highly conductive core, and the shell of Ni(OH)₂ nanofilms increases the density of catalytic active sites. The interesting morphology and the brilliant electrocatalytic efficacy of designed hybrid, encourage us to design a multi-mode sensor for glucose and H₂ O₂ screening. The NFs-Ni(OH)₂ /ZnO@C MBs/GCE glucose sensor presented good sensitivities (647.899 & 161.550 μA (mmol L^-1 )^-1  cm^-2 ), a quick response (<4 s), lower limit of detection (0.04 μmol L^-1 ), and wide detection range (0.004-1.13 & 1.13-5.02 mmol L^-1 ). Similarly, the same electrode revealed excellent H₂ O₂ sensing features including good sensitivities, two linear parts of 3.5-452 and 452-1374 μmol L^-1 , and detection limit of 0.03 μmol L^-1 as well as high selectivity. Thus, the development of novel hybrid core-shell structure is useful for potential applications in glucose and H₂ O₂ screening from environmental and physiological samples.