Abstract: Although glucose electrochemical sensors based on enzymes play a dominant role in market, their stability remains a problem due to the inherent nature of enzymes. Therefore, glucose sensors that are independent on enzymes have attracted more attention for the development of stable detection devices. Here we present an enzyme-free glucose sensor based on Ni(OH)₂ and reduced graphene oxide (rGO). The as-fabricated sensor still exhibits excellent electrocatalytic activity for detecting glucose under enzyme independent conditions. The enhanced catalytic performance may due to synergistic effect as follows: (i) the interaction between the Ni²⁺ and π electron of graphene induces the formation of the β-phase Ni(OH)₂ with higher catalytic activity; (ii) the frozen dry process works as a secondary filtration, getting rid of poorly formed Ni(OH)₂ particles with low catalytic activity; (iii) the rGO network with good conductivity provides a good electronic pathway for promoting electron transfer to reduce the response time. Based on the synergistic effect, the sensor exhibits a wide linear detection range from 0.2 μmol/L to 1.0 μmol/L and a low detection limit (0.1 μmol/L, S/N=3). The excellent detection performance, as well as the easy and low-cost preparation method, suggests the promising applicability of the sensor in the glucose detection market.

Key words: Glucose sensing, Non-enzyme sensor, Graphene, 2D material, Ni(OH)₂ nanosheet