A facile approach to synthesis methylene blue/reduced graphene oxide nanocomposite and simultaneous determination of dopamine and uric acid

A novel and highly selective electrochemical sensing platform based on combination of methylene blue (MB) and graphene oxide (GO) was performed for simultaneous detection of dopamine (DA) and uric acid (UA). The structure and morphology were characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive spectrometer analysis (EDS), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectrometer (FTIR). And the electrochemical behaviors of the electrode were further explored by cyclic voltammetry (CV), electrochemical impedance analysis (EIS), and differential pulse voltammetry (DPV). The structural and morphological characterization demonstrated that MB was successfully introduced into the GO interlayer. In addition, the electrochemical behavior of CV and EIS showed that the electron transfer of MB/RGO nanocomposites was greatly improved, and DA and UA were subjected to a typical adsorption control process on MB/RGO modified electrode. Meanwhile, under the DPV test, the linear response ranges for DA and UA were 15 to 268 μM and 30 to 521 μM, respectively. In comparison to the previous literature, there is a lower detection limit of 5.9 μM (DA) and 8.5 μM (UA), respectively. Moreover, the proposed sensor shows high stability, reproducibility and good anti-interference, indicating that MB/RGO nanocomposite has great potential in preparing sensors detection of DA and UA. Graphical abstract