Construction of bimetallic oxy-hydroxides based on Ni(OH)2 nanosheets for sensitive non-enzymatic glucose detection via electrochemical oxidation and incorporation

Due to the ease of synthesis and large specific surface area, Ni(OH)2 nanosheets have emerged as promising electrochemical sensing materials, attracting significant attentions in recent years. Herein, a series of oxy-hydroxides based on Ni(OH)2 nanosheets, including NiOx/Ni(OH)2@NF and (MNi)Ox/Ni(OH)2@NF (M = Co, Fe, or Cr), are successfully synthesized via the electrochemical oxidation and incorporation strategies. Electrochemical tests demonstrate that these Ni(OH)2-based oxy-hydroxides exhibit excellent electrochemical oxidation activity for glucose in alkaline electrolyte. Among these, (CoNi)Ox/Ni(OH)2@NF displays higher sensitivity of 3590.3 μA mM-1 cm-2 across a broad linear range of 10 μM to 1.14 mM, with a rapid current response time of less than 4 s. The superior sensing performances of (CoNi)Ox/Ni(OH)2@NF are attributed to the formation of abundant Ni3+ species and reactive-O atoms due to the electrochemical oxidation, and the synergistic effects of Co/Ni active sites resulted from the electrochemical incorporation process. In addition, the (CoNi)Ox/Ni(OH)2@NF demonstrates good stability and reproducibility for glucose sensing. This work fully leverages the significance of surface reconstruction of Ni(OH)2, providing new insights for the application of transition metal-based oxy-hydroxides materials in bio-sensing.