Carbon Nano-based Composite Nanomaterial Modified Electrode And Its Detection Of Phenolic Substances And Glucose

As an important branch of the sensor,electrochemical sensor is one of the most important research areas in modern analytical science due to its simple operation,easy to miniaturization,low cost,excellent selectivity,high sensitivity and good stability.Electrochemical sensor has been widely used in many fields,such as disease diagnosis,drug analysis and environmental monitoring.Nanomaterials possess many remarkable physical and chemical properties.It has the advantages of high specific surface area,thermal stability,good electron conduction and mechanical properties.In comparison to other carbon substrates（such as carbon nanotubes,graphene,etc.）,carbon black nanopartical meterials are extremely favourable due to their strong adsorption ablity,significantly lower cost,high catalytic,widespread availability and high surface area-to-volume ratio.Therefore,it has broader application prospects in the field of electrochemical research.Among nano-materials,metal nanomaterials have become attractive materials in electrochemical sensors because of their high specific surface area and high surface energy.These advantages make the surface atoms of metal have good activity.Therefore,it has many unique photoelectric properties and catalytic activities.When it modifies the electrode,the sensitivity of the electrode can be increased significantly.The application of metal nanoparticles in modified electrode can be used to catalyze some substances and to detect them quickly.Metal oxide is of great interest as they are cheaper than noble metal,have large surface area,have wide energy band gap and can improve the electrochemical performance of materials,therefore metal oxide is employed widely in gas sensors,photocatalysts,supercapacitors,lithium-ion batteries,and electrochemical detection.The work of this paper focuses on the application of the carbon black nanoparticles and its composite materials in the electrochemical sensor research.The main content is divided into the following three parts:Ⅰ.The preparation of glassy carbon electrode modified with titanium dioxide/carbon black nanoparticles and its application for the simultaneous electrochemical determination of hydroquinone and catechol.In this study,a novel method for simultaneous determination of hydroquinone and catechol was established with titanium dioxide/carbon black nanocomposite as modified material.The cyclic voltammetry,impedance method,differential pulse voltammetry and other electrochemical characterizations and measurements were used.Theexperimentalresultsshowthatthemodifiedelectrode TiO₂NPs-CBNPs/GCE can simultaneously detect hydroquinone and catechol in the range from 4μmol/L to 90μmol/L,1μmol/L to 90μmol/L with detection limit of0.118μmol/L and 0.129μmol/L（S/N=3）.Ⅱ.Glassy carbon electrode was modified with silver nanoparticles/carbon black nanocomposites and electrochemical detection of glucose.In this study,silver nanoparticles/carbon black nanocomposites was composed by chemical reduction method.The electrochemical behavior of modified electrode were studied by the methods of cyclic voltammetry,AC impedance and chronoamperometry.The modified electrode has shown effective catalytic behavior in the studies of glucose oxidation.Under optimization conditions,The linear relationship voltammogram response of glucose was observed in the range from 0.1mmol/L to 13 mmol/L with a detection limit of 0.014 mmol/L（S/N=3）.In addition,ascorbic acid,uric acid,dopamine have no obvious interference on the detection of glucose.The results are satisfactory for the detection of glucose in real samples.Ⅲ.Electrochemical determination of p-Nitrophenol by cobalt oxide nanoparticles/carbon black modified glassy carbon electrode.In this work,cobalt nanoparticles were introduced by electrodeposition and further oxidized to form cobalt oxides.A new modification method for electrochemical detection of p-Nitrophenol was constructed by using cobalt oxides/carbon black composite nanomaterials as modified materials.The electrochemical behavior of this electrode were studied by cyclic voltammetry,AC impedance and differential pulse voltammetry.The experimental results show that the modified electrode Co _OX/CBNPs/GCE can significantly enhance the reduction peak current of p-nitrophenol.This method is fast,simple and sensitive.The linear range of p-nitrophenol detected by Co _OX/CBNPs/GCE electrode is 1⁴00μmol/L,and the detection limit is 0.243μmol/L（S/N=3）.The electrochemical sensor has a good effect on the detection of p-nitrophenol in real water and has a good application prospect.