Electrochemical Determination of Metronidazole Using a Glassy Carbon Electrode Modified with Nanoporous Bimetallic Carbon Derived from a ZnCo-Based Metal-Organic Framework

ZnCo-based metal-organic frameworks (MOFs) based on ZIF-8 and ZIF-67 were synthesized at room temperature. Direct carbonization of the ZnCo-MOF under nitrogen atmosphere produced a nanoporous ZnCo/C composite which exhibited a large surface area (1111.499 m2∙g−1) and narrow pore-size distribution (1 ∼ 2 nm). A glassy carbon electrode was modified with the nanoporous ZnCo/C and Nafion for the electrochemical determination of the antibiotic metronidazole by linear sweep voltammetry. Under optimal conditions, the reduction peak current (observed at −0.66 V vs Ag/AgCl) increased linearly with increasing metronidazole concentration in the range of 0.05–100 μM, with a detection limit estimated at 17 nM. These results are attributed to the large surface area, porous structure, high nitrogen content, and synergistic effects of the Zn and Co constituents. The sensor was satisfactorily used for metronidazole analysis in pharmaceutical samples.