The Co²⁺-induced synergistic effect in nickel 5-methylsalicylate MOFs electrocatalysts for enhanced glucose electrooxidation

Strategically tailoring the electronic configuration of electrocatalysts through the incorporation of additional metal ions serves as a highly effective approach for boosting electrochemical glucose oxidation performance. In this work, a series of Co-doped nickel 5-methylsalicate (MeSA) metal organic framework (MOF) composites (NiCo-MeSA) were developed via a one-step solvothermal method. The NiCo-MeSA complex exhibits a porous MOF structure, promoting the electrolyte diffusion and access to active sites. Moreover, the introduction of Co²⁺ effectively regulates the electronic structure of Ni-MeSA catalysts, thereby improving both the selectivity toward glucose and stability of electrochemical glucose oxidation reaction (GOR). The optimized NiCo-MeSA nanocomposites demonstrate high sensitivity of 4.55 mA·mM⁻¹·cm⁻², an ultralow detection limit of 0.54 µM (S/N = 3, where N indicates response standard deviation and S represents the calibration curve’s slope), and exceptional long-term stability. Significantly, this design paradigm demonstrates broad applicability, as evidenced by the successful extension to isostructural NiM-SA analogs (M = Mn, Fe, Cu) under identical synthetic conditions, establishing bimetallic 5-methylsalicylate framework as a versatile and robust electrocatalyst platform.