Ce-MOFs derived cerium phosphate for high-efficiency electrochemical detection of metronidazole

In this work, three kinds of cerium phosphate (CePO4) with different morphologies, namely rod-like CePO4 (R–CePO4), spherical CePO4 (S–CePO4), and platelike CePO4 (P–CePO4), were successfully hydrothermally synthesized by using Ce-MOFs (MOF ​= ​metal-organic framework) as templates. The CePO4 materials synthesized by this method not only retain the morphology of Ce-MOFs, but also possess good crystallinity and high specific surface areas, suggesting the universality of this method. Among them, the S–CePO4 modified glassy carbon electrode (S–CePO4@GCE) shows the highest electrochemical activity. When S–CePO4@GCE was used to detect metronidazole (MNZ), a wide linear range of 5.0–3980 ​μM, a low detection limit (S/N ​= ​3) of 3.6 ​μM, good stability, and high selectivity could be obtained. This may be due to the good redox properties of cerium, the higher specific surface area of mesoporous S–CePO4, and the hydrogen bonding interactions between S–CePO4 and MNZ. In addition, the constructed electrode S–CePO4@GCE can also be used for analyzing MNZ in the real medicines and the water samples. This work provides a useful method to prepare high-efficiency CePO4-based electrode materials.