Synthesis of g-C ₃ N ₄ @CuMOFs nanocomposite with superior peroxidase mimetic activity for the fluorometric measurement of glucose

Herein, a novel metal-organic framework (MOF) based nanocomposite with efficient catalytic behavior is reported including flake-like copper (II) MOF (CuMOF) and graphitic C ₃ N ₄ nanosheets (g-C ₃ N ₄ ). The g-C ₃ N ₄ @MOF nanocomposite was simply prepared by solvothermal synthesis of CuMOF in the presence of g-C ₃ N ₄ . The characterization analyses using scanning electron microscopy (SEM), X-ray diffractometry (XRD) and some other techniques demonstrated a nano-porous flake-like structure for the synthesized CuMOF, which enveloped the g-C ₃ N ₄ nanosheets. Furthermore, the investigation of catalytic behavior of synthesized nanomaterial was implemented on H ₂ O ₂ based reactions. The fluorometric and colorimetric experimentations illustrated that the accompanying of g-C ₃ N ₄ with CuMOF had a remarkable positive effect on the catalytic behavior of obtained g-C ₃ N ₄ @MOF. This effect was described based on the improved affinity of nanocomposite to adsorb H ₂ O ₂ and also synergistic action of its components on the dissociation of H ₂ O ₂ to hydroxyl radicals. Finally, the analytical application of high catalytic activity of new g-C ₃ N ₄ @MOF was designed for the rapid and simple measurement of glucose in blood. After the enzymatic oxidation of glucose, the fluorometric method was applied for the analysis of produced H ₂ O ₂ using terephthalic acid as peroxidase substrate. The system led to the ultrasensitive glucose determination in the concentration range of 0.1–22 μM, with a detection limit (3S/m) of 59 nM.