MIL-101 (Fe)-NH₂ metal-organic framework/graphene oxide nanocomposite modified screen-printed carbon electrode for...

In the present study, we report the synthesis of MIL-101 (Fe)-NH₂ metal-organic framework/graphene oxide (MIL-101 (Fe)-NH₂ MOF/GO) nanocomposite, which was synthesized through simple solvothermal method. Various characterization techniques including Field-emission scanning electron microscopy (FE-SEM), Energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) were employed for the morphological and structural characterization of the synthesized nanocomposite. Then, the prepared MIL-101 (Fe)-NH₂/GO nanocomposite was drop-casted on the screen-printed carbon electrode (SPCE) to fabricate a simple, rapid, and sensitive electrochemical sensing platform for 2,4-dichlorophenol (2,4-DCP) determination in the water samples. Comparative analysis using cyclic voltammetry (CV) showed that the MIL-101 (Fe)-NH₂/GO/SPCE significantly improved the oxidation reaction of 2,4-DCP with observation of higher detection current at lower over-potential compared to unmodified SPCE. This observation can be related to the synergistic combination of MIL-101 (Fe)-NH₂ MOF and GO sheets. The linear response of MIL-101 (Fe)-NH₂/GO/SPCE sensor for determining 2,4-DCP using voltammetric measurements was observed in the range of 0.001-440.0 μM with a low detection limit (LOD) of 0.5 nM and a high sensitivity of 0.2026 μA μM^-1. Finally, the modified SPCE efficiently exhibits its high accuracy in detecting 2,4-DCP in water samples, demonstrating remarkable recovery percentages of 97.5-104.4 %.