Construction Of Sensing Interface And Electrochemical Performance Of Carbon-Based Composite Coating On Glassy Carbon Electrode

At present,commonly used detection and analysis techniques include gas chromatography,liquid chromatography,gas chromatography-tandem mass spectrometry,liquid chromatography-tandem mass spectrometry,and so on.These methods inevitably have drawbacks such as cumbersome sample pre-treatment,high detection costs,and complex analytical operations,which cannot meet the needs of simple,fast,efficient,and portable on-site testing.Compared with traditional detection technologies such as complex sample pre-treatment,expensive equipment and instruments,high requirements for specialized operation,and time-consuming,electrochemical sensing detection technology not only overcomes these shortcomings,but also can achieve accurate,low-cost,and portable on-site detection.Therefore,electrochemical sensing detection technology has great potential research value and good application prospects in the field of analysis and detection.It is worth noting that the performance of electrochemical sensing detection technology is closely related to the modification materials on the electrode surface.In recent years,carbon materials with good conductivity,large specific surface area,and excellent electrocatalytic performance have gradually become a research hotspot in the field of electrochemical sensing and detection.In this article,three modified materials were prepared,one is a bi-functionalized one-dimensional carbon nanomaterial,and the other two are functionalized integrated composite materials based on highly conductive carbon materials.They were used for the detection of gallic acid and methyl parathion,respectively,demonstrating the advantages of simplicity,speed,sensitivity,and satisfactory detection limits,selectivity,repeatability,and reproducibility.The specific research content is as follows:（1）Using bi-functionalized（graphitized and carboxylated）multi-walled carbon nanotubes（GR-MWCNTs-COOH）as modification materials,graphitized carboxylated multi-walled carbon nanotubes（GR-MWCNTs-COOH）was used to modify the surface of glass carbon electrode（GCE）by a simple drop coating method to create a sensing interface for the gallic acid（GA）detection.GR-MWCNTs-COOH has a large specific surface area,high conductivity,good hydrophilicity,and a one-dimensional nanotube like structure.The fabricated sensor exhibited satisfactory electrochemical detection performance with a limit of detection（LOD）in the range of 0.01 to 10μM of 0.0032μM.In addition,the sensor also has excellent repeatability,reproducibility,anti-interference,and practicality.（2）Bifunctional GR-MWCNTs COOH@Zirconia（Zr O₂）nanocomposites were prepared by ultrasound assisted strategy（GR-MWCNTs-COOH@Zr O₂）.GR-MWCNTs-COOH and Zr O₂nanocomposites were used to modify the surface of GCE by a simple drop coating method to create a sensing interface for the methyl parathion（MP）detection.GR-MWCNTs-COOH has a large specific surface area,high conductivity,good hydrophilicity,and a one-dimensional nanotube like structure.Zirconia（Zr O₂）nanoparticles have good affinity for the phosphate group of MP,which helps to improve the selective recognition and enrichment performance of the electrode surface.The fabricated sensor possessed limit of detection（LOD）in the range of 0.01 to 10μM of 0.00135μM.In addition,the sensor also shows excellent repeatability,reproducibility,selectivity and practicability.（3）Ginkgo nut-derived porous carbon（GNDPC）was prepared by a high-temperature activation strategy,and GNDPC@β-Cyclodextrin（β-CD）nanocomposites（GNDPC@β-CD/GCE）was prepared by ultrasound assisted strategy.GNDPC andβ-CD nanocomposites were used to modify the surface of GCE by a simple drop coating method to create a sensing interface for the methyl parathion（MP）detection.GNDPC has a high conductivity carbon network with a large specific surface area and three-dimensional interconnection,β-CD improves the dispersibility of GNDPC and has good enrichment performance for MP molecules.The synergistic effect of the two has achieved GNDPC@β-CD/GCE sensor for ultra-sensitive detection of MP.The limit of detection in the concentration range of 0.005 to 15μM was 4.52 n M,with good recovery of MP in real samples,indicating the excellent performance of the sensor and its high practicality.