Study On The Detection Of Non-steroidal Anti-inflammatory Drugs By Electrochemical Sensors Based On Copper Composite Materials

Non-steroidal anti-inflammatory drugs have anti-inflammatory and antipyretic effects,relieve pain,and treat rheumatic diseases.However,because such drugs can cause gastrointestinal,liver and kidney,blood and nervous system side effects and cause death in some patients,such drugs are determined The amount of residue in the body is very important.Current methods for the detection of non-steroidal anti-inflammatory drug residues include HPLC and LC-MS,but most of them are limited due to expensive and time-consuming instruments.Because electrochemical detection methods have the advantages of easy sample preparation,fast response,simple instrument and low price,the electrochemical determination of non-steroidal anti-inflammatory drugs has attracted more and more attention.Therefore,this paper selects transition metal sulfides with the advantages of low cost,high electrocatalytic activity,and metal-like conductivity,and carbon materials with large specific surface area and excellent conductivity as the main body,and they are passed through with other components.Simple synthesis process for compounding,successfully designed and prepared two copper-based composite materials La-CuS and CuNPs-MWCNTs,and used them as modified electrode materials,Thus,two new types of electrochemical sensors were constructed.The detection and analysis of aspirin hydrolysates-salicylic acid(SA),acetaminophen(AP)and acetaminophen(2-AP)are realized.The main contents of this thesis are as follows:1.The La-doped CuS nanoplate composite material was successfully prepared by a simple and convenient one-step hydrothermal method,and a high-sensitivity electrochemical sensing platform was constructed.The La was verified by SEM,EDX,XRD and various electrochemical methods.Successful preparation of CuS composite materials.Due to the low electron transfer resistance of the sheet-like stacked structure of CuS,it provides a fast and effective way for electron conduction.The doping of the rare earth element La leads to a smaller crystal size and a larger effective surface area,which accelerates the transfer of electrons.And further improve the electrocatalytic activity of salicylic acid,the synergistic effect of the two enhances the conductivity and electrocatalytic performance of the electrode material,La-CuS/GCE compares the naked GCE and CuS/GCE to the detection of salicylic acid SA Has a significantly enhanced electrochemical response.After optimizing the material,under the best conditions,differential pulse voltammetry(DPV)was used to study the electrochemical behavior and oxidation mechanism of SA on La-CuS/GCE in 0.1 M PBS(pH=5)solution.It is confirmed that the SA oxidation on the La-doped CuS/GCE surface is regulated by the diffusion process,and the electro-oxidation is a process of transferring two electrons and two protons.Therefore,an electrochemical detection method for salicylic acid was established.In0.1 M PBS,the prepared La-CuS/GCE get a low detection limit,which is 0.52μmol/L(S/N=3),and the linear range was 1 μmol/L-20 μmol/L and 20 μmol/L-500μmol/L.The method has the advantages of simplicity,environmental protection,low cost,etc.,and shows good selectivity,high sensitivity,excellent anti-interference ability and stability for the detection of salicylic acid.It was successfully applied to the detection of salicylic acid in actual samples,and the recovery rate was satisfactory.2.A simple and fast one-pot water bath method was used to prepare a composite material with multi-walled carbon nanotubes as a substrate and Cu nanoparticles loaded on it.The successful preparation of CuNPs-MWCNTs composites was assisted by SEM,Raman,XRD and various electrochemical methods.And can clearly observe the metal copper nanoparticles attached to the surface of the carbon nanotubes interspersed with each other,thus constructing a unique electrochemical sensor,realizing both paracetamol(AP)and acetaminophen(2-AP)Simultaneous electrochemical detection of various target molecules.Compared with bare GCE and MWCNTs/GCE,CuNPs-MWCNTs/GCE has significantly enhanced electrochemical response to AP and 2-AP detection,and the potential difference is 99 m V,which can realize simultaneous detection.The excellent electrochemical performance is mainly attributed to the synergy between CuNPs with small particle size,large specific surface area,and more reactive centers,and MWCNTs with excellent electrical conductivity and large electrochemically active specific surface area.The mutual support between the carbon nanotubes makes up for the shortcomings of easy agglomeration between nano metal particles,so as to give full play to the advantages of the two components,and greatly improve the conductivity and electrocatalytic activity of the modified electrode.The experiment examined the influence of factors such as pH and sweep speed on the experimental results,and studied the relevant electrochemical reaction mechanism.After optimizing the material,under the best conditions,the cyclic voltammetry was established in a 0.1 M PBS solution(CV)Electrochemical analysis method for simultaneous determination of AP and 2-AP,the prepared CuNPs-MWCNTs/GCE showed lower detection limits as AP=0.066 μmol/L(S/N=3),2-AP= 0.053 μmol/L,and the linear range was AP: 1-500 μmol/L,2-AP: 1-200 μmol/L.The modified electrode has excellent sensitivity,good reproducibility,long-term stability and the ability to resist interference,and it is excellently applied to detect AP and 2-AP in real samples,and the recovery rate is satisfactory.