Preparation Of Dye Polymer Sensor And Its Application For Nitrofuran Determination In Aquaculture Water

As a chemical product,dyes are mainly used for printing and dyeing of fibers or other materials.Because the molecular structure of organic dyes has conjugated structures and electron donors such as amino hydroxyl groups,it can undergo electrochemical polymerization and can be used for preparation of sensors.The research uses dye alizarin red and acid chrome blue K as materials and glassy carbon electrode(GCE)as the base electrode to carry out the electrochemical procedure,the preparation process,electrochemical performance and the sensors' application for nitrofuran determination was discussed respectively in this paper.The main research contents are as follows:1.A poly(alizarin red)film sensor(PAR/GCE)was prepared by electrochemical polymerization of alizarin red on a GCE by employing cyclic voltammetry(CV),and its preparation process and detection application conditions were studied in detail.The results show that the concentration,acidity of the alizarin red solution,and the scan rate,potential window of CV showed a great impact on the morphology and electrochemical performance of the PAR film formed on the GCE.The optimal preparation process conditions are: immersing a GCE in a 0.2 mmol/L alizarin red solution(p H = 2.0 B-R),in a potential range of-1.0V to 2.2V,and running at a scan rate of 125 m V/s keeping 15 cycles.SEM,cyclic voltammetry,electrochemical impedance spectroscopy(EIS),and differential pulse voltammetry(DPV)were performed to characterize the morphology and electrochemical characteristics of the polymer film.The results showed that the morphology of the polymer film was granular and showed good conductivity.The electrical signals generated by nitrofuran drugs on GCEs have a significant enhancement effect.The linear range and detection limit of nitrofurazone(NFz),furantoin,and furazolidone are: 3.0?50.0 ?mol/L,0.33 ?mol/L;10.0?40.0 ?mol/L,0.73 ?mol/L;50.0?140.0 ?mol/L,1.56 ?mol/L,respectively.The sensor was prepared under the optimal preparation process conditions and applied to the detection of NFz in aquaculture water.The spike recovery of sample was 94.5%?104.8%,indicating that the sensor is suitable for the detection of nitrofuran drugs in aquaculture water.2.Cyclic voltammetry was used to prepare a poly acid chrome blue K modified sensor(PACBK/GCE)and applied to nitrofurazone determination in aquaculture waters.By optimizing the sensor preparation process,a PACBK film sensor with excellent electrochemical performance and responsive to nitrofuran was prepared.Studies have shown that the conditions such as the concentration of acid chrome blue K,acidity,type of supporting electrolyte,scan rate and potential window of cyclic voltammetry have significant effects on the electrochemical performance of the sensor.The optimal preparation conditions are as follows: immersing a GCE in 0.5 mmol/L acid chrome blue K solution(p H = 8.0 PBS),in the range of-1.0?2.0V,under the scan rate of 75 m V/s,run the CV scan for 18 cycles.The surface morphology of the sensor prepared under this condition showed a state of fine sheet connection and multiple voids.CV and EIS showed that the effective surface area was increased and the conductivity was excellent.The sensor shows good reproducibility and selectivity performance.After preparation,it can be repeatedly used after being activated.Under optimized detection conditions,it was applied to the determination of nitrofuran drugs in aquaculture water.The linear range and limit of detection for NFz,furantoin,and furazolidone were: 0.2?15.0 ?mol/L,0.028 ?mol/L;5.0?30.0 ?mol/L,0.072 ?mol/L;10.0?60.0 ?mol/L,0.19 ?mol/L,respectively.The electrochemical reaction process of NFz on PACBK film sensor showed the characteristics of being controlled by adsorption.The sensor was applied to the detection of NFz in aquaculture waters,and the spike recovery was between 88.6% and 110.6%,indicating that the sensor shows practical value in the detection of NFz.