A novel electrochemical sensor for glucose detection based on Ag@ZIF-67 nanocomposite

In this paper, we demonstrated the first application of a Co-based porous metal-organic framework (MOF) ZIF-67 as the glucose electrochemical sensor. The ZIF-67 modified glassy carbon electrode (GCE) showed an excellent catalytic activity towards glucose oxidation. Meanwhile, to improve the electrocatalytic performance of the modified electrode, a novel Ag@ZIF-67 nanocomposite was fabricated through a sequential deposition-reduction method. The Ag@ZIF-67/GCE exhibited an enhanced catalytic activity towards glucose oxidation. The electrocatalytic performance of Ag@ZIF-67 with different Ag loadings was investigated, and the results indicated that with the Ag contents increasing from 0% to 0.5%, the response time of the modified electrode was shorten by more than two times, and the sensitivity was increased by two times and a half. The Ag-0.5%@ZIF-67GCE exhibited excellent electrocatalytic performances in the glucose concentration range of 2-1000 μM, including a high sensitivity of 0.379 μA μM−1 cm−2, a low detection limit of 0.66 μM (S/N = 3) as well as good selectivity and stability.