Snowflake-shaped poly(3-thiophenemalonic acid) combined with carbonized ZIF-8@ZIF-67 hollow polyhedra for sensitive electrochemical detection of metronidazole

Developing a facile and effective assay method is crucial due to the potential harm of metronidazole (MNZ) antibiotics to both human health and the environment. Herein, snowflake-shaped poly(3-thiophenemalonic acid, 3-TPA) combined with a carbonized core–shell-type ZIF-8@ZIF-67 (C-ZIF-8@ZIF-67) hollow polyhedra modified glassy carbon electrode (GCE), denoted as C-ZIF-8@ZIF-67/P3TPA/GCE, was fabricated by electropolymerization followed by the electrodeposition strategy. The resulting sensor demonstrates a significant electrocatalysis effect for the reduction reaction of MNZ, exhibiting a broad linear range (0.1–20, 20–800 μM) with a low limit of detection (LOD, 3S/N) of 0.024 μM. Furthermore, it has been successfully applied to determine MNZ in tablets and lake water. A synergistic effect between P3TPA and C-ZIF-8@ZIF-67 is elucidated through density functional theory (DFT) calculations. Consequently, this research introduces a sensitive and effective method for monitoring MNZ in real samples.