Prepared And Applied Of Hydrogen Peroxide And Cytochrome C Of Electrochemistry Sensors

On the basis of introducing the type and the preparation methods of electrochemical sensors, and theirapplications in analytical chemistry, a series of the good performance of electrochemical sensors of Cyt cand H₂O₂were prepared using a variety of electrode modified materials and many methods. Moreover, theirapplications were explored respectively. The research works were briefly described as follows:1. Electrochemical Properties of Tungstogermanate and Electrocatalytic Performance ofGeW₁₁Co/P-oPD/GC Electrode to the Reduction of H₂O₂Cyclic voltammograms revealed Co-substituted trimeric tungstogermanate containing Kegginfragments on GC electrode had two couples of reversible redox peaks in acid aqueous. Their differences ofpeak potential were31mV and35mV, respectively, which corresponded to respectively two two-electronreductions accompanying by the addition four protons and three protons. In addition, the electrochemicalprocess was controlled by adsorption. Further, the tungstogermanate modified GC electrode withfunctionalization by poly（o-phenylenediamine）（P-oPD） was prepared handily by electropolymerization.Experiments demonstrated that GeW₁₁Co/P-oPD/GC electrode can electrocatalyze the reduction ofhydrogen peroxide, which had good stability and quick response.2. Determination of H₂O₂with Polylysine and MWCNTs modified Glassy Garbon ElectrodeThe PLL/MWCNTs/GC modified electrode was prepared by electropolymerization method. Peroxidehydrogen can be electrocatalytic reduced on the modified electrode and determined with cyclicvoltammetric method. The optimal detection conditions were researched in detail. Experiments showedthat there existed linear relationship between the peak current and the concentration of peroxide hydrogenin the range of1.3×10^-2～4.3×10^-4mol/L in pH7.10.05mol/L PBS solution, with the detection limit of1.5×10^-4mol/L. The modified electrode was prepared handily and had good stability and quick response.3. Study of Immobilization and Direct Electrochemistry of Cytochrome c at Nano-gold film ModifiedElectrodeThe Cs-NanoAu being modified on the surface of Au electrode with Self-assembly and moreassembling Cytochrome c, the Cyt c/Cs-NanoAu/Au electrode was prepared. As shown by experimental results, effective immobilization and direct electrochemistry of Cyt c was achieved successfully at thenano-film modified electrode. Cyclic voltammogram curves showed obviously a pair of well-defined andreversible peaks between0.13and0.28V （vs.Ag/AgCl）. The results of the experiments indicated that thepeak currents of Cyt c were linear to the scanning rates. The linear equation is i_pc=0.06364+0.00351υ（r=0.9972）, which indicated that the electrode process was controlled by adsorption. The film modifiedelectrode gived good stability, which provides a good foundation to the development and application of thethird generation biosensors.4. Study of Direct Electrochemistry of Cytochrome c at Core-shell structure Fe₃O₄@Au NanoparticlesModified Electrode and Electrocatalytic Performance to the Reduction of H₂O₂Based on a novel carboxylated core-shell structure Fe₃O₄@Au nanoparticles as promoter, a new nanomaterial modified electrode was prepared. The direct electron transfer between Cyt c and the electrode wasachieved on this nanofilm modified electrode. Further, the Cyt c/Fe₃O₄@Au/PDDA/GC electrode wasprepared by absorption, which can acheieve the direct electron transfer of Cyt c and electrocatalyze thereduction of hydrogen peroxide. It can be developed and manufactured further as a new electrochemistrybiosensor to hydrogen peroxide.