Electrochemistry Research Of Electrochemical Sensor Based On Nanocomposite Materials

In this paper, the platinum/gold （Pt/Au） composite materials,thiolated chitosan/chitosan/carbon nanotubes （CS-TGA/CS/MWCNTs）composite and chitosan/graphene （CS/GR） composite were prepared. Theplatinum/gold composite materials which have excellent catalytic effectwere used in the preparation of the nonenzyme sensor on the hydrogenperoxide, while the carbon nano-materials possessing good conductiveproperties good adsorption properties and the porous materials possessinggood adsorption properties were used in the preparation of heavy metalion sensors, their performance were studied in various ways.Theexperimental results showed that the prepared heavy metal ion sensors had good performance and can be used for a variety of heavy metal ionsdetection. And the prepared Pt/Au nanotubes possess good electocatalysisactivity own to its special surface.1. The Pt/Au nanotubular electrodes were prepared by constantpotential electrodeposition on the template of Ag wire. The surface of theelectrode was characterized by Scanning Electron Microscope （SEM） andX-ray Photoelectron Spectroscopy （XPS）. Their electrocatalysis propertiesof hydrogen peroxide were studied by electrochemical methods. ThePt/Au nanotubular electrode showed a linear range of2×10^-62×10^-5mol·L^-1to hydrogen peroxide, with a detection limit of9.04×10-7mol·L^-1.2. The chitosan （CS） was first used to prepare thiolated chitosan（CS-TGA）, which then was mixed with chitosan according to a certainproportion. Then the MWCNTs were added to prepareCS/CS-TGA/MWCNs/ITO electrode. The electrode was used to detectPb²⁺as a sensor. Their morphology and structure of the composite werecharacterized by Infrared Spectroscopy （IR） and SEM and their electrochemical behavior were sstudied by electrochemical method. Theeffect of electrolyte, pH and adsorption time were also discussed. Underthe optimized experimental conditions, the sensor showed a linear range of2.0×10^-92.0×10^-8mol·L-1to Pb²⁺with a detection limit of9.53×10^-7mol·L-1according to3σ rule. The prepared heavy ion sensor displayedexcellent electrochemical response, high sensitivity.3. The graphite powder was used to prepare graphite oxide （GO） andgraphene （GR）. The grapnene was mixed with chitosan according to acertain proportion to prepare CS/GR composite. The composite was usedto prepare CS/GR/GC electrode. Porous material chitosan has goodadsorption properties to heavy metal ions and graphene has a very goodelectrical conductivity. The electrode can effectively detect the heavymetal ions. Their morphology and structure were characterized by InfraredSpectroscopy （IR） and Transmission Electron Microscope （TEM）. Also,the effect of content, pH and adsorption time were studied byelectrochemical method. Under the optimized experimental conditions, the sensor showed a linear range of1.0×10^-91.5×10-8mol·L^-1to Cu2+with a detection limit of4.25×10^-7mol·L^-1according to3σ rule. Theprepared heavy metal ion sensor displayed excellent electrochemicalresponse, high sensitivity.