Based on bimetallic Fe Co MOFs electrochemical sensor with a low detection limit for trace copper ions detection

Environmental contamination by heavy metal ions poses significant health risks, emphasizing the urgent need for effective detection methods. In the work, it develops a bimetallic Fe Co MOFs electrochemical sensor for trace copper ions detection in water, using a NaOH-mediated synthesis to modify MOFs materials. Iron ion doping introduces a bimetallic site, significantly enhancing the conductivity of the original ZIF-67. The addition of reduced graphene oxide (RGO) further improves conductivity due to its folded structure, which facilitates greater MOF deposition on the electrode surface. Additionally, the incorporation of Nafion enhances the stability of the MOF in aqueous environments. Sensitivity tests show effective detection of Cu 2+ in the concentration range of 0.01–1 μM, with a LOD of 6.54 nM. And the sensor has exceptional stability, reproducibility, and interference resistance. The sensor demonstrated successful application in detecting Cu 2+ in water samples, showing potential for broader applications in monitoring other heavy metal ions in environmental water samples. • The high conductivity ZIF-67 was formated by doping with iron ions at the bimetallic site. • The bimetallic Fe-ZIF-67/RGO/Nafion/GCE Electrochemical Sensor was constructed. • The sensitive detection of Cu 2+ was achieved by SWSV with a detection limit of 6.54 nM. • Fe-ZIF-67/RGO/Nafion/GCE can be applied for the detection of Cu 2+ in water samples