Investigation Of Electrochemical Glucose And Nitrite Sensing Based On Three Kinds Of Ni-based Nanocomposites

The application of nanocomposites with special structure and excellent properties to construct new electrochemical sensing interfaces,which can effectively improve the analytical performance of electrochemical sensors,provides a higher platform for the development and research of sensors.In addition,the above researches have become the frontier technology of electroanalytical chemistry.In this thesis,the electrochemical sensors based on three kinds of nickel-based nanocomposites were constructed.The electrochemical and electrocatalytic properties of nickel-based nanocomposites with different compositions and structures were studied.New methods of electrochemical sensing for the detection of glucose and nitrite were established.The above studies enrich the catalytic application of nickel-based nanocomposites in electrochemical sensors.The full text included three chapters and the main research contents were as follows:1.NiPt hollow nanospheres were synthesized by replacement reaction,and then a sensor based on NiPt/GO nanocomposites was fabricated and applied to the electrochemical detection of glucose with PDDA functionalized graphene oxide as supporting materials.The results showed that the linear range of NiPt/GO nanocomposites modified electrode for electrocatalysis of glucose under alkaline condition was 1.0 μM-2.78 mM,the sensitivity was 39.7 μA mM-1 cm-2,and the detection limit was 0.45 μM.2.NiCo/PPy/RGO nanocomposites were prepared by in situ chemical polymerization and co-reduction method,and a glucose electrochemical sensor based on the NiCo/PPy/RGO nanocomposites was constructed.The study revealed that the sensor displayed an excellent electrocatalytic activity to the oxidation of glucose.The liner range for glucose detection was 0.5 μM-4.1 mM,with a detection limit of 0.17 μM,a sensitivity of 153.5 μA mM-1 cm-2,and excellent selectivity and stability.3.Pt/Ni(OH)2/MWCNTs nanocomposites were prepared by two-step chemical method,and a nonenzymatic NO2-electrochemical sensor was fabricated.The linear range of the sensor for NO2-detection was 0.4 μM-5.67 mM,the sensitivity was 145 μA mM-1 cm-2,and the detection limit was 0.13 μM.It is expected that the idea of combining Ni(OH)2 with MWCNTs to prepare nanocomposites enriches the functionalization of MWCNTs.The constructed sensor can be used for the detection of NO2-in different milk.