Electrochemistry Of Horseradish Peroxidase And Giucose Oxidase Immobilized On Modified Electrodes And Enzyme Biofuel Cell

In this dissertation,we report on a Glucose/H₂O₂ enzyme biofuel cell by integrating a enzyme-catalyzed cathode with horseradish peroxidase(HRP) and anode with glucose oxidase(GOx).The mixture of coomassie brilliant blue and multi-walled carbon nanotube-modified glassy carbon electrode(CBB G-250/ MWNT/GC) has been fabricated by us.Cyclic voltammetric results show a pair of well-defined and nearly symmetrical redox peaks,which correspond to the direct electron transfer of HRP and GOx,Apparent electron transfer rate constant(k_s) are 4.68s^-1å’Œ2.8 s^-1 respectively and their formal redox potential E^0' are almost independent on the scan rates.The dependence of E^0' on the pH of the phosphate buffer solution confirms the redox process involving protons.In addition,the result of the experiment proves that HRP and GOx on the surface of modified electrode retain their bioelectrocatalytic activity to the reduction of H₂O₂ and oxidation of glucose.The proposed method was simple,making it potentially attractive for the application to biosensor and biofuel cells.Besides,we assemble a enzyme biofuel cell with bipolar rooms based on electrochemistry of every single electrode.Using grape juice beverage as the substrate of anode is better then D-glucose.The reason is that grape juice beverage contains ascorbic acid which can be oxidized.We use potassium ferricyanide and ferrocene as mediators of cathode and anode respectively.The substrate are H₂O₂ and glucose,and we add some ascorbic acid to anode chamber.The power,open circuit voltage and short-circuit current of biofuel cell are 499.2 e^-9W,437mV and 11.72μA respectively.Finally,we optimized the performance of the cell.The dependence of voltage and current on the amount of carbon nanotube,coomassie brilliant blue and glucose has been investigated.The maximum power,open circuit voltage and short-circuit current are 681.7e^-9W,443mV and 12.47μA respectively by orthogonal experiment analysis.