Electrochemical sensing of dopamine using a Ni-based metal-organic framework modified electrode

A Ni-based metal-organic framework (Ni-MOF) modified electrode was fabricated for electrochemical detection of dopamine. The Ni-MOF was synthesized by ionothermal synthesis method using an ionic liquid as a template. The morphology and composition of the Ni-MOF were characterized by scanning electron microscope, X-ray diffraction, thermogravimetric analysis, and attenuated total reflection Fourier transform infrared spectroscopy. Electrochemical responses of the Ni-MOF modified electrode toward dopamine were performed using differential pulse voltammetry. The electrochemical sensing performance of the Ni-MOF modified electrode toward dopamine was improved by the introduction of ionic liquid with a wide linear range (0.2-100 mu mol L-1), and a low detection limit (60 nmol L-1). Further studies indicated that the modified electrode exhibited great selectivity to dopamine in complex mixtures, and the Ni-MOF modified electrode also has excellent stability and reproducibility. Moreover, the analysis of real samples confirmed that the modified electrode has a certain reliability.