Preparation Of Novel Molecularly Imprinted Electrochemical Sensors And Study Of Detection Performance On Pesticide Residue

The wide use of pesticides results in pesticide residues problems.It becomes huge threat to environmental safety and human health.People trying to alleviate the status quo.Understanding the status of the residues is the prerequisite while detecting residues is the key.As a result,developing an efficient and simple pesticide residues detection method is imminent.Aiming at this situation,a molecularly imprinted electrochemical sensor with specific choice recognition ability to pesticides is prepared to detect and analyse the residues.The mainly study content of the thesis is divided into the following two parts:1.With chitosan as function matrix,imidacloprid/ thiamethoxam as template molecules,glutaraldehyde as crosslinking agent,using potentiostatic deposition to prepare molecularly electrode and build imidacloprid molecularly sensor(IMI-MIP/F-CNTs/GCE)and thiamethoxam molecularly sensor(TMX-MIP/F-CNTs/GCE).Then investigate the new sensors' detection performance with electrochemical methods(cyclic voltammetry(CV),differential pulse voltammetry(DPV),electrochemical impedance spectroscopy(EIS))while build the equivalent circuit model.The results showed that: The novel molecularly imprinted electrochemical sensors(IMI-MIP/F-CNTs/GCE and TMX-MIP/F-CNTs/GCE)were prepared successfully.The apparent surface area of the two electrodes were increased significantly comparing with the bare electrode.They have good imprinting effects and good recognition performance to template molecules.Meanwhile,an EIS equivalent circuit model was set up.The calculation of the equivalent circuit element parameters proved that it can simulate the sensing mechanism of the sensor detection effectively.2.Suppress the IMI-MIP/F-CNTs/GCE and TMX-MIP/F-CNTs/GCE with IMI and TMX,then analyse the uninhibited sensor and the inhibition sensor with differential pulse voltammetric scan,record the peak current data,calculate the inhibition rate,at last,analyse the data.Do parallel experiment in order to detect the response performance and stability of the two sensors.The results showed that: The IMI-MIP/F-CNTs/GCE and TMX-MIP/F-CNTs/GCE have specific target molecules recognition performance and select performance to IMI and TMX.Meanwhile,the sensors which prepared with potentiostatic deposition had good stability and long service life.In short,the results of this thesis have certain reference value to the detection and removment of residues.Meanwhile,the results devoted to the application of sensors.