Electrochemical Sensing Based On Molybdenum Disulfide Nanocomposites

MoS₂ nanosheets,with excellent semiconductor properties,abundant base/edge active sites,large specific surface area and strong adsorption capacity,have become a favorable electrode functional material in electrochemical sensing research.The electrocatalytic performance of MoS₂ nanosheets can be improved effectively by combining MoS₂ nanosheets with other conductive nanomaterials.In this thesis,three kinds of MoS₂ composites were prepared,based on which three electrochemical sensors were constructed to investigate the electrocatalytic oxidation of dopamine,rutin and p-nitrophenol,respectively.The main research topics are as follows:（1）MoS₂ nanosheets were electrochemically pretreatment while Au NPs were electrodeposited on the surface of MoS₂ nanosheets by one-step cyclic voltammetry.An electrochemical sensor for dopamine detection was constructed.The sensor displayed a wide linear range from 0.2μmol·L^-1 to 1.0 mmol·L^-1 with high sensitivity of 215.7μA·(mmol·L^-1)^-1·cm^-2 and low detection limit of 0.2μmol·L^-1 using amperometry.The linear range of dopamine detection by differential pulse voltammetry was 0.2–80.0μmol·L^-1.The sensor showed good sensitivity with an estimated value of 2.1μA·(μmol·L^-1)^-1·cm^-2 and the limit of detection（LOD）was 0.2μmol·L^-1.It was used to detect dopamine in serum with a recovery rate of 106.5%-109.4%.（2）The composites of noble metal and MoS₂ nanosheet was prepared by water bath reduction method.An electrochemical sensor based on Au@Pt/MoS₂ composites was constructed for the detection of rutin.The sensor displayed a linear range from 0.02μmol·L^-1to 1.0μmol·L^-1 with high sensitivity of 149.3μA·(μmol·L^-1)^-1·cm^-2 and LOD was 3 nmol·L^-1.It could also be used for the detection of rutin in onion with an average recovery of 96.35%.（3）Metal-organic frameworks based carbon/MoS₂ composites were prepared by solvothermal method.An electrochemical sensor based on MOFs-C/MoS₂ composites was constructed for the detection of p-nitrophenol.The sensor displayed a wide linear range from0.5μmol·L^-1 to 500.0μmol·L^-1 with high sensitivity of 3.2μA·(μmol·L^-1)^-1·cm^-2 and LOD was0.04μmol·L^-1.It could also be used for the detection of p-nitrophenol in water with a recovery of 95.50%-101.1%.