Preparation of CuO/rGO Nanocomposite with Rice Granular Structure and Its Application to Detect Glucose

Abstract

In order to enhance the electrochemical detection performance for glucose, graphene oxide (GO) was introduced during the preparation process of micron-sized rice granular CuO. A nano-sized rice CuO/rGO composite chemically modified electrode with good conductivity was prepared and used for the enzyme-free detection on glucose. The morphology and structure of the samples were characterized by scanning electron microscope, X-ray diffraction, Raman spectroscopy and N2 adsorption desorption tester. The electrochemical properties of the prepared modified electrode were tested by cyclic voltammetry, amperometric experiments and AC impedance testing. The results show that the prepared nanocomposite still retains the rice grain structure of the original CuO, but the particle size is reduced in to nanometer scale. When the mass ratio of CuO and rGO is 3.5:1, the modified electrode has the strongest current response to glucose: in the range of 0.01 to 2.53 mmol·l−1, there is a good linear relationship and the linear equation is I pa (Ma) = (2.81 ± 0.08) × 10−2 + (9.63 ± 0.06) × 10−2 c (mmol·l−1), R = 0.999. The detection limit is 0.047 mol·l−1 (S/N = 3) and the sensitivity is 1746.16 μA·mmol−1·L·cm−2. At the same time, the prepared modified electrode has good selectivity, reliability, repeatability and stability for glucose.