Hierarchical dense Ni−Co layered double hydroxide supported carbon nanofibers for the electrochemical determination of metronidazole in biological samples

Scientific research reports have shown that long-term use of chemical and biological drugs such as Metronidazole (MNZ) can lead to certain human health issues due to its genotoxic, genotypic, carcinogenic and mutagenic type side effects in the biological samples. Therefore, the rapid exploration and rational design of electrocatalyst materials, reliable electrochemical techniques, and essential strategies to fabricate novel electrochemical sensing devices for the detection of drugs in the biological samples are of utmost interest. Herein, we developed a facile strategy to fabricate a novel electrode material consisting of conductive hierarchical dense nickel-cobalt layered double hydroxide material grown on electrospun carbon nanofibers (CNF–NiCo-LDH), which was synthesized via a simple hydrothermal method. Because of their hierarchical dense unique interconnected architecture, the CNF–NiCo-LDH deposited onto a glassy carbon electrode (GCE) exhibited improved electrocatalytic response toward metronidazole (MNZ). The fabricated electrode delivered a higher cathodic peak current for MNZ at a low peak potential of −0.54 V in the presence of 20 μM MNZ in 0.05 M phosphate-buffered solution ((PBS; pH 7). The fabricated electrode showed a wide linear response for the reduction of MNZ at concentrations from 3 to 57 nM, an extremely lower detection limit (LOD) of 0.13 nM, and a high sensitivity of 1.294 μA nM⁻¹ cm⁻². The developed electrode also showed interference-free sensing performance and excellent long-term stability. Because of its electrochemical performance, the CNF–NiCo-LDH-GCE provides a simple, fast, and effective electrochemical sensor for the detection of MNZ at the ultra-trace level in industrial and pharmaceutical applications.