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

In this work, three kinds of cerium phosphate (CePO 4 ) with different morphologies, namely rod-like CePO 4 (R–CePO 4 ), spherical CePO 4 (S–CePO 4 ), and platelike CePO 4 (P–CePO 4 ), were successfully hydrothermally synthesized by using Ce-MOFs (MOF ​= ​metal-organic framework) as templates. The CePO 4 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–CePO 4 modified glassy carbon electrode (S–CePO 4 @GCE) shows the highest electrochemical activity. When S–CePO 4 @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–CePO 4 , and the hydrogen bonding interactions between S–CePO 4 and MNZ. In addition, the constructed electrode S–CePO 4 @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 CePO 4 -based electrode materials. Rod-like, spherical and plate-like CePO 4 were synthesized using Ce-BTC, Ce-MOF-808 and Ce 6 -BTB as templates, respectively, and were developed as an electrochemical sensor for metronidazole sensing. • Rod-like, spherical and platelike CePO 4 were synthesized using three Ce-MOFs as templates. • The spherical CePO 4 (S–CePO 4 ) synthesized with Ce-MOF-808 has a larger specific surface area. • When S–CePO 4 @GCE is used to electrochemically detect MNZ, it has a lower detection limit and a wider linear range. • The constructed electrode has been successfully applied to the detection of MNZ content in tablets and various water bodies.