| Chemically modified electrode which developed from the mid-1970 s, now has been widely used in many fields such as electrochemistry, chemistry and electrical analysis.Because of its easy preparation and operation, chemically modified electrode has been also widely used in the detection of medicines, foods, and environmental samples.Nanomaterials have unique structure, morphology and physical and chemical properties. Electrochemical sensors based on nanomaterials perform great sensitivity due to its excellent adsorpted and catalytic capacities. The use of the special properties of nano-materials used to modify electrode, can effectively promote the electron transfer rate of the electrode surface, and the nature of a particular electrode can be given to achieve the desired reaction on the electrode surface with high selectivity. Play its excellent catalytic electrochemical activity, and then build the electrochemical sensor platform, has become an electrochemical or electrochemical analysis of research. This paper is based on chemically modified graphene electrode / nanomaterials prepared samples of traditional Chinese medicine, environmental samples and food samples were simultaneously measured or detected. The content of this paper is divided into the following three parts:1. Electrochemical behaviors of rutin at oxygen-functional multi-walled carbon nanotubes/graphene hybrid nanomaterials modified electorode and its application.In this section, through the dropping method, the hybrid nanomaterials composite film modified electrode of MWCNTs-COOH/GR/GCE was fabricated. The electrochemicalbehavior of rutin was studied on the MWCNTs-COOH/GR/GCE and the electrochemical parameters of rutin were calculated. The results indicated that the MWCNTs-COOH/GR/GCE showed excellent characteristics, such as good resistance ability against interferences(such as ascorbic acid and other oxidizable amino acids), high sensitive and good electrochemical catalytic activity to the analysis of rutin. Under the optimal experimental conditions, linear relationships between the values of the oxidation peak current and the concentration of rutin was obtained in the ranges of 0.01 to 50.0×10-6mol/L, with the correlation coefficient of 0.9984, the limit of detection was 4.6×10-9 mol/L(S/N=3). The method can be successfully applied to the determine rutin in pagodatree flower bud and troxeruti tables and the results were satisfactory.2. Simultaneous determination of Orange G and Orange II in industrial wastewater by a novel Fe2O3/MWCNTs/OP modified carbon paste electrodeA highly sensitive electorchemical sensor for the simultaneous determination of orange G and orange II based on a carbon paste electrode modified with Fe2O3/oxygen functional multi-walled carbon nanotubes/turiton X-100 has been developed. The characterized of the Fe2O3 and multi-walled carbon nanotubes had been verification according to the XRD, SEM, TEM and electrochemical methods. The determination conditions, including pH, scan rates and the volume of MWCNTs-COOH/OP suspension at the modified electrode were optimized. Under the optimum experimental conditions, the orange G and orange II could be linearly detected by differential pulse voltammetry. The oxidation peak current and the concentration of orange G and orange II were obtained in the oranges of 0.1 to 20.0×10-6 mol/L and 0.2 to 50.0×10-6 mol/L, respectively, with the correlation coefficient of 0.9997 and 0.9975, respectively, the limit of detection were5.0×10-8 mol/L and 1.0×10-7 mol/L, respectively(S/N=3). The method can be successfully applied to the determination of orange G and oreange II in industrial wastewater and the results were satisfactory.3. Electrochemical behavior of clenbuterol at sulfonated graphene sheets/oxygen-functional multi-walled carbon nanotubes hybrid nanomaterials modified electrode and its applicationA highly sensitive electorchemical sensor for the determination of clenbuterol basedon a glass carbon electrode modified with SGSs/MWCNTs-COOH has been developed.The characterized of the SGSs and MWCNTs-COOH had been verification according to the FTIR, UV, SEM and electrochemical methods. The determination conditions, including pH,scan rates and the volume of SGSs/MWCNTs-COOH suspension at the modified electrode were optimized. Under the optimum experimental conditions, linear relationships between the values of the oxidation peak current and the concentration of clenbuterol was obtained in the ranges of 0.01 to 50.0×10-6 mol/L, with the correlation coefficient of 0.9996, the limit of detection was 4.6×10-9 mol/L(S/N=3). The method is simple, selective and sensitive. It was successfully applied to the determination of clenbuterol in liver samples and the results were satisfactory. |
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