Electrochemical Sensing Research Of PEDOT-base Ternary Composites In The Field Of Food Quality And Safety

poly（3,4-ethylenedioxythiophene）（PEDOT）has prominent physical and chemical properties such as high electrical conductivity,good chemical stability and biocompatibility with biological media,making it a widely concerned material.Due to its high permeability and conductivity,PEDOT can be used as a good dispersant for easy stacking materials and a construction component of electronic pathways to promote the uniform dispersion of functional sites and mass charge transfer of sensing materials,thereby providing a large accessible area to achieve efficient substance transfer or provide sufficient species storage.In addition,reasonable introduction of transition metal compounds and two-dimensional materials with electrochemical activity can not only improve and enhance the physical and chemical properties of PEDOT,but also endow the composite with rich functional properties.Therefore,according to different application scenarios,new PEDOT-based composites with specific functions can be designed by using simple and effective synthesis strategies to accurately control the structure composition and active site characteristics,which can promote the application of PEDOT-based materials in the field of food quality and safety in electrochemical sensing.Based on the application of PEDOT-based material electrochemical sensor in the field of food quality and safety,this paper designed,functionalized and prepared three PEDOT-based ternary composite materials,and systematically studied the electrocatalytic activity and electrochemical sensing performance of PEDOT-based composite materials.The specific research work is as follows:1.Pt/Pd-PEDOT/nitrogen-doped graphene（NGE）composite was developed through one-pot method.Firstly,the coral-like porous organic framework PEDOT was obtained through the REDOX reaction of Pd²⁺and EDOT monomer,which improved the contact area of the composite.The loading of noble metal nanoparticles improves the conductivity of the organic framework structure.The introduction of NGE as a substrate promotes electron transport and expands the dispersion of PEDOT particles.Pt/Pd-PEDOT/NGE exhibits a unique three-dimensional porous structure,which can provide more active sites for electrochemical reactions and a favorable transport path for the osmotic adsorption of electrons,ions,and biomolecules.The Pt/Pd-PEDOT/NGE-based sensing platform for the detection of caffeic acid exhibits a wide linear range with a low detection limit,high sensitivity,and strong anti-interference ability due to its inherent advantages and unique structural characteristics.In addition,the sensing platform showed appropriate recovery and accuracy,confirming the feasibility of the electrochemical sensor in practical application.2.Usingtitaniumcarbide（Ti₃C₂T_x）,poly（3,4-ethylenedioxythiophene）:poly（styrene sulfonate）（PEDOT:PSS）and ruthenium nanoparticles（Ru NPs）as raw materials,the multilayer structure of Ru/PEDOT:PSS/Ti₃C₂T_x ternary composite was synthesized by one-pot method.Ti₃C₂T_x is encapsulated with conductive PEDOT,which effectively prevents the self-stacking of Ti₃C₂T_x nanosheets and successfully constructs the inter-layer electronic transmission pathway,thereby improving the stability and conductivity of PEDOT:PSS/Ti₃C₂T_x structure,alleviating the volume expansion/contraction effect,and preventing the structure collapse.PEDOT:PSS/Ti₃C₂T_x presents a Shandong pancake shaped three-dimensional hierarchical structure and a large electrode/electrolyte contact area,providing rich adsorption sites for Ru NPs loads.Ru/PEDOT:PSS/Ti₃C₂T_x composite shows high sensitivity and low detection limit for Sudan I under the synergistic effect of each component,which is better than that of most reported detection methods.In addition,Ru/PEDOT:PSS/Ti₃C₂T_x has been successfully applied to the detection of Sudan（?）in tomato sauce and chili sauce.Meanwhile,this work also provids an ingenious and effective strategy for the design and development of high-performance Sudan（?）sensor by comparison with traditional instrumental analysis method.3.Using magnetic Pd-Fe₃O₄ nanoclusters as catalytic activator and hierarchical PEDOT:PSS/NS-Ti₃C₂T_xascarrier,thehierarchical Pd-Fe₃O₄/PEDOT:PSS/NS-Ti₃C₂T_x was successfully constructed by colloid adsorption characteristics and ice bath slow oxidation.In this way,palladium nanoparticles can be completely adsorbated and deposited by colloid adsorption,which solves the problems that noble metal nanoparticles are difficult to collect and environmentally unfriendly.NS-Ti₃C₂T_x in-situ doped with N and S increases the electron density of Ti₃C₂T_x itself,which is conducive to the adsorption of electroactive substances.PEDOT:PSS intercalation of NS-Ti₃C₂T_x between nanosheets alleviates the inherent self-stacking of Ti₃C₂T_x and constructs a three-dimensional electronic pathway mesh,improving the structural stability and conductivity of NS-Ti₃C₂T_x and promoting the osmotic adsorption and mass charge conduction rate of analyte.Therefore,the Pd-Fe₃O₄/PEDOT:PSS/NS-Ti₃C₂T_x sensing platform shows high sensitivity and low detection limit with a wide linear range,good stability,and strong anti-interference in the detection of parathion-methyl.Compared with traditional instrumental analysis methods,Pd-Fe₃O₄/PEDOT:PSS/NS-Ti₃C₂T_xdetection platform exihits a receivable accuracy and good recovery.In this work,Pd-Fe₃O₄/PEDOT:PSS/NS-Ti₃C₂T_x is used as the sensitive material to provide an effective synthesis path for the preparation of magnetic terpolymer,which provides a good idea for the development of parathion-methyl sensor.