Study And Application Of Nano Metal Cadmium/Cerium Compounds Modified Electrode

Nanometer materials modified electrodes due to its uniquephysical and chemical properties, has become an important part inthe electrochemical research. It has widely used in the field ofpharmaceutical analysis, biological sample analysis andenvironmental monitoring etc. In recent years, rare earthpolynuclear iron cyanide film modified electrodes due to the specialproperties of the rare earth metal elements has been widely used inmany aspects. It has become a new hotspot of electrochemicalresearch. Three kinds of chemical modified electrodes were studiedin this paper:1. CdSe nanoparticles （CdSeNPs） have been successfullysynthesized via a sulfhydryl water phase method and characterizedby scanning electron microscope （SEM）. The CdSeNPs wereimmobilized on glassy carbon electrode via a drop coating method,the electrochemical behavior of mercury ion was investigated on the CdSe nanoparticles modified electrode, and the electrodereaction mechanism has been discussed in detail. The experimentresults showed that the modified electrode significantly improvedthe electrocatalysis activity toward the oxidation of mercury ion inpH=1.0KCl-HCl buffer solution. The linear range for mercury iondetermination ranged from1.5×10^-9to3.0×10^-6mol/L with adetection limit of5.0×10^-7mol/L. The modified electrode exhibitedgood repeatability and stability, which can be used fordetermination of mercury ion.2. Cadmium sulfide nanoparticles/Polypyrrole/Potassiumferrocyanide modified glassy carbon electrode was formed viaelectrochemical polymerization and electrochemical depositionmethod, the electrochemical behavior of nitrite ion wasinvestigated on the modified electrode, and the electrode reactionmechanism has been discussed. The electrode exhibited highelectrochemical activity and sensitivity in pH=6.8Na₂HPO₄-NaH₂PO₄buffer solution, and showed a linear response fornitrite ion solution of1.0×10^-9～4.0×10^-6mol/L and a detection limitof2.0×10^-6mol/L. The method for determination of nitrite ioncontent is a better way and it has a good prospect.3. A steady of Hb/CeHCF/GCE was obtained by succeaafullyimmobilizing hemoglobin （Hb） on a glassy carbon electrode, which was modified using cerium ferricyanide（CeHCF） films. Itsoptimum experimental conditions were found, and get a new type ofhydrogen peroxide biosensor. The electrochemistry behavior ofCeHCF/GCE in PBS （pH=6.4） and the direct electron transfermechanism of Hb were discussed. The results show that the ceriumferricyanide films provide a gentle immobility environment forhemoglobin, the direct electron transfer between Hb and theelectrode is realized, and successfully used for the detection ofhydrogen peroxide.