Design and Fabrication of NiMn Layered Double Hydroxide/Reduced Graphene Oxide as Electrochemical Sensor for Simultaneous Detection of Ascorbic Acid, Dopamine and Uric Acid

In this paper, NiMn layered double hydroxide (NiMn LDH) was quickly synthesized by coprecipitation method. Then NiMn LDH nanosheets and graphene oxide (GO) nanosheets were obtained by ultrasonic exfoliation technology, which were combined with each other by electrostatic force to obtain NiMn LDH–GO composites. The material was characterized by various techniques including X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectrometer. The results of morphology and structure characterization showed that NiMn LDH–GO composite was successfully synthesized and modified it on the surface of glass carbon electrode (GCE), and LDHs were distributed on the surface of GO. Then NiMn LDH-ERGO/GCE was prepared by green and pollution-free electrochemical reduction method. Cyclic voltammetry, differential pulse voltammetry and electrochemical impedance were used to study the electrochemical properties. The results showed that NiMn LDH-ERGO/GCE could realize the simultaneous determination of ascorbic acid, dopamine, uric acid in phosphate buffer solution, and the detection limits were severally 4.11 μM in the linear range of 23.32–235.15 μM, 0.03 μM in the linear range of 0.83–3.15 μM and 0.14 μM in the linear range of 1.18–5.67 μM (S/N = 3.0). In addition, NiMn LDH-ERGO/GCE showed good stability, reproducibility, and anti-interference ability.