Synthesis of manganese porphyrins/electrochemical reduction of graphene oxide nanocomposite to simultaneously detect dopamine and uric acid under the interference of ascorbic acid

This study reported the synthesis of ERGO-MnTMPyP and its electrochemical detection performance for dopamine (DA) and uric acid (UA). The nanocomposite was based on the electrostatic interaction between graphene oxide (GO) nanosheets and manganese porphyrins (MnTMPyP). The material was characterized using various techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectrometer (FT-IR), demonstrating successful synthesis. Various electrochemical tests, including cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV), were performed to analyze the electrochemical characteristics of modified glass carbon electrodes (GCE). The modified electrode exhibited a significant reduction in electron transfer resistance, decreasing to 100.9 Ω. Compared with previous studies, the modified electrode reveals a unique performance to effectively detect DA (208 mV) and UA (328 mV) simultaneously with the presence of ascorbic acid (AA) interference. The detection peaks of DA and UA were apparently separated with the detection limits of 0.29 μM in the linear range of 2.23–10.76 μM and 0.64 μM in the linear range of 2.23–10.76 μM (S/N = 3), respectively.