Nonenzymatic\nElectrochemical Sensing Platform Based\non 2D Isomorphic Co/Ni-Metal–Organic Frameworks for Glucose\nDetection

Abstract

Two-dimensional metal–organic framework (MOF)\ncrystalline\nmaterials possess promising potential in the electrochemical sensing\nprocess owing to their tunable structures, high specific surface area,\nand abundant metal active sites; however, developing MOF-based nonenzymatic\nglucose (Glu) sensors which combine electrochemical activity and environmental\nstability remains a challenge. Herein, utilizing the tripodic nitrogen-bridged\n1,3,5-tris­(1-imidazolyl) benzene (TIB) linker, Co²⁺ and\nNi²⁺, two 2D isomorphic crystalline materials, including\nCo/Ni-MOF {[Co (TIB)]·2BF₄} (<b>CTGU-31</b>)\nand {[Ni­(TIB)]·2NO₃} (<b>CTGU-32</b>), with\na binodal (3, 6)-connected <b><i>kgd</i></b> topological\nnet were firstly synthesized and fabricated with conducting acetylene\nblack (AB). When modified on a glassy carbon electrode, the optimized\nAB/CTGU-32 (1:1) electrocatalyst demonstrated a higher sensitivity\nof 2.198 μA μM^–1 cm^–2, a wider linear range from 10 to 4000 μM, and a lower detection\nlimit (LOD) value (0.09 μM, <i>S</i>/<i>N</i> = 3) compared to previously MOF-based Glu sensors. Moreover, AB/CTGU-32\n(1:1) exhibited desirable stability for at least 2000 s during the\nelectrochemical process. The work indicates that MOF-based electrocatalysts\nare a promising candidate for monitoring Glu and demonstrate their\npotential for preliminary screening for diabetes.