Construction Of Electrochemical And Electrochemiluminescence Sensor Based On Nanocomposite Electrode

Nanocomposite materials prepared from metal, carbon, semiconductor and polymerhave been widely used in electrochemical and electrochemiluminescence (ECL). Inelectrochemistry, the characteristic of electrode was closely related to its surface properties.Nanocomposite materials not only have outstanding performance of each nanomaterial, butalso existed the combination with several materials. Accordingly, they exhibited uniqueelectrical, optical and catalytic properties. In this work, new nanocomposite materials withpalladium nanoparticles were obtained via chemical synthesis or electrochemicaldeposition. The composite modifed electrodes were applied to the oxidation of simpleorganic molecules, such as formaldehyde, methanol, ethanol. Formaldehyde is one of theimportant raw materials in industrial production. So people often suffer from it in daily life.Composite electrochemical sensor based on palladium nanoparticles can be used todevelop the rapid, sensitive and easy method for the detection of formaldehyde. In addition,methanol and ethanol were used as fuel in direct alcohol fuel cell. Nanocompositematerials with palladium nanoparticles could improve the utilization, the catalytic activityand anti-poison capability of the anode in direct alcohol fuel cell application.In the ECL biosensors, nanomaterials were taken as modification electrode materials,as carrier of ECL labels and ECL-emitting species. Tyrosinase was a key enzyme ofcatecholamine and epinephrine belonged to catecholamines. It was well known thatepinephrine was an important material about signal transportion in the central nervoussystem of mammals. Thus, we constructed nano-silicon carbide aselectrochemiluminescence biosensor for epinephrine.This thesis would be divided into four sections:Chapter I: Introduction of noble metal nanopaticles, carbon nanomaterials, syntheticmethods of noble metal and carbon nanocomposites, the application of the nanocompositematerials in the electrochemical and ECL were described in detail.Chapter II: The composite electrode was fabricated by palladium nanoparticles andgraphene (PdNPs/Graphene/GCE). The scanning electron microscopy (SEM) was usedto characterize the surface of the composite electrode, the electro-catalytic oxidation offormaldehyde in the composite electrode were studied by the electrochemical technology. Preparation of composite electrodes and experimental conditions were optimized anddeveloped a novel method for detecting the concentration of formaldehyde.Chapter III: The new composite electrode was obtained from silicon carbidesupported Pd nanoparticles by chemical reduction, which was applied to theelectrocatalytic oxidation of methanol and ethanol. The characterization of the compositefilms was executed by transmission electron microscopy (TEM) and X-ray photoelectronspectroscopy (XPS). The electrochemical performance of the composite electrode showedthat it had superior catalysis for the oxidation of methanol and ethanol in an alkalinemedium.Chapter IV: Based on the outstanding property of nano-silicon carbide, the hydrogenperoxide ECL sensor was constructed. As hydrogen peroxide was produced in the reactionbetween tyrosinase and epinephrine, based on which, an ECL biosensor for epinephrinewas designed. Its ECL intensity and the concentration of epinephrine had good linearrelationship in the range of1×10-9~5×10-6M with the detection limit of8×10-10M.