| Ractopamine（Rac）is an artificially synthesizedβ-agonist that belongs to the phenolic hydroxyl group,and it’s a member of lean.In the original period of time,Rac was widely used as a therapeutic drug for pulmonary disease and asthma,and exhibits excellent curative effects.At the same time,it also was found that Rac can improve the feed efficiency and carcass leanness of livestock.However,the gradually accumulate of Rac may cause cardiovascular and central nervous diseases,which will be serious threat to people’s health.Nitrites have a bactericidal effect,so they are extensively used as food preservation.At the same time,nitrites are also used as fertilizing agents.However,the excess ingestion of nitrites will be harmful for human health because it can cause irreversible oxidation of hemoglobin to methemoglobin in the body,which has no oxygen carrying ability.Moreover,also have some carcinogenic effects.So it is a potential threat to human health.Ephedrine（Eph）is widely used for its beneficial effects on asthma and certain allergic diseases.However,excessive intake can cause great damage to the nerve center.And Eph is an important raw material for the synthesis of precursor chemicals.This will bring great harm to the society.Therefore,fast,sensitive,simple and accurate methods for the determination of Rac,nitrites and Eph are urgently required.In this work,we have prepared three sensors for determination of Rac,nitrites and Eph,respectively.The performance of the sensors were also evaluated.（1）The 3-D macro-porous Cu（3D-Cu）film was formed on a Cu disc electrode surface through the method of hydrogen bubble dynamic template.To improve the sensitive of the electrode,gold was deposited onto the surface of 3D-Cu electrode（Au@Cu3D）to construct a Rac electrochemical sensor.The performance of the Au@Cu3D electrode was studied by cyclic voltammetry and differential pulse voltammetry,the results showed that Au@Cu3D exhibits the highest current response toward RAC electro-oxidation.Further research shows that this sensor possess the good reproducibility,stability and potential applications in real sample analysis.（2）The graphite rod electrode（GRE）was modified as followers:the GRE was treated in Na2SO4 solution from-1.0 V to+3.0 V（vs Ag/AgCl）.Then,the hydrothermal preparation of copper-metal organic framework（Cu-MOF）was dropped onto the surface of GRE,thus an Cu-MOF/GRE was prepared successfully.Finally,a layer of gold is deposited to form Au/Cu-MOF/GRE electrode.Cyclic voltammetry and chronoamperometry results showed that Au/Cu-MOF/GRE had a good electrochemical determination performance toward nitrite.Further research showed that the sensor has good selectivity and stability and can also be applied in real sample analysis.（3）Ru（bpy）32+/OMC-Nafion/GCE was prepared by drop-coating method and ion exchange method,and was applied to the electrochemical detection of ephedrine.Cyclicvoltammetryandchronoamperometryshowedthat Ru（bpy）32+/OMC-Nafion/GCE had a good electrochemical response to ephedrine.Further research shows that the sensor has good performance. |
