Cu-MOF/N-doped GO nanocomposites modified screen-printed carbon electrode towards detection of 4-nitrophenol

Metal-organic framework-based nanocomposites have recently received much attention in electrochemical sensors. Herein, copper-metal organic framework/nitrogen-doped graphene oxide (Cu-MOF/NGO) nanocomposites were synthesized using a solvothermal approach. The materials were characterized by field emission scanning electron microscopy/energy-dispersive X-ray spectroscopy, high-resolution transmission electron microscopy, Brunauer-Emmett-Teller analysis, X-ray diffraction analysis, thermogravimetric analysis, and UV-visible spectroscopy. The Cu-MOF/NGO nanocomposites were applied in the modification of a screenprinted carbon electrode (SPCE) towards detection of 4-nitrophenol (4-NP) using differential pulse voltammetry. Moreover, the electrode materials were characterized using Raman spectroscopy, atomic force microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. In ferricyanide and ferrocene redox probes, the Cu-MOF/NGO/SPCE showed improved current response and charge transfer kinetics. The Cu-MOF/NGO/ SPCE showed a lower limit of detection (0.035 mu mol L-1) and limit of quantification (0.116 mu mol L-1) within a linear range of concentration (0.5-100 mu mol L-1). The developed electrode demonstrated good analytical features of selectivity, repeatability, and reproducibility. The application of the Cu-MOF/NGO/SPCE was found to be successful in the determination of 4-NP in wastewater samples, with good recovery results in the range of 103.00 to 107.33%.