Construction Of PEDOT:PSS-coated PET Flexible Plastic Electrode And Its Electrochemical Sensing Analysis Of Typical Pollutants

As an efficient,fast,sensitive and environmentally friendly analysis method,electrochemical sensing is gradually applied in various fields such as medical inspection,environmental pollutant monitoring and food inspection.In order to improve the detection accuracy and extend the range of application,the development of new working electrodes,especially the new requirements for flexible electrodes,has become the focus of electrochemical sensor research.Among them,the working electrode is the core component that determines the performance and application range of electrochemical sensors.The development of electrochemical sensors with high sensitivity,high response and flexible bending performance has become a research hotspot.This also fully reflects people paying attention to life and health and yearning for a better life.For this purpose,polyethylene terephthalate(PET)was used as the sensor substrate in this paper.The PEDOT:PSS film was constructed on the surface by spin coating technology,and the film was further treated with methanesulfonic acid(MSA)under heating to remove the part of PSS,forming MSA-t-PEDOT:PSS/PET film with high conductivity.The preparation and processing process does not affect the integrity of the PET substrate,and retains its advantages of stability and flexibility.MSA-t-PEDOT:PSS/PET film can be used instead of bare glass carbon electrodes to construct flexible sensors.In Chapter 2,the CD-f-MSA-PEDOT:PSS/PET flexible film electrode was constructed by immersing the MSA-t-PEDOT:PSS/PET film into the β-cyclodextrin(β-CD)solution through the use of electrostatic self-assembly technology.X-ray photoelectron spectroscopy(XPS)and atomic force microscopy(AFM)confirmed the composition and surface group of the film electrode.The electrochemical sensor based on CD-f-MSA-PEDOT:PSS/PET flexible film electrode has excellent electrochemical response to dopamine and catechol,while the detection limits respectively are 13.68 and 15.86 nmol/L,and have good reproducibility,stability and anti-interference.The film electrode can maintain a stable electrochemical response under different states of bending and crease,showing excellent mechanical stability and flexibility.In Chapter 3,the nitrogen-doped graphene(NG)was synthesized by hydrothermal method with graphene oxide(GO)as raw material,and the dispersion was evenly dropped onto the surface of the MSA-t-PEDOT:PSS/PET film to prepare NG-f-MSA-PEDOT:PSS/PET flexible film electrode.XPS,infrared spectroscopy(FT-IR),Raman spectroscopy(Raman)and scanning electron microscopy(SEM)confirmed the successful preparation and recombination of NG,and explored the relationship between the morphological structure of the film surface and electrochemical properties.The electrochemical sensor based on this flexible film electrode has been successfully applied to the sensitive detection of acetaminophen with a good linear response in the concentration range of 0.1-270 μmol/L,and the detection limit is 17.09 nmol/L.In addition,the film electrode can maintain a stable electrochemical response under different states of bending and crease,showing excellent mechanical stability and flexibility.