Direct Electrochemistry Of Redox Proteins On Nanomaterials Modified Electrode

Biomacromolecule including proteins and enzymes are the primary groups of life. Directelectrochemistry of proteins and enzymes has aroused great interest in biological andbioelectrochemical field. Studies on direct electrochemistry of redox proteins/enzymes can be used togain their thermodynamics and the kinetic property, understand the mechanistic of electron exchangeamong proteins in biological systems and physiological action. Moreover, direct electron transferbetween immobilized ertzyme and underlying electrode can establish a foundation for fabricating newkinds of mediator-free biosensor, biofuel cell and bioreactors. In a sense, the essence of studying lifeprocess is to study the electron transfer process. Therefore, uses electrochemistry method to study theelectron transfer process of proteins have the special superiority.The present paper mainly take the new nanomaterials as the biological carrier and the molecularwire to construct a biological member/nanomaterials on the nanometer contact surface, thenanostructured materials can promote the electron transfer of redox proteins and enzymes. The fulltext divides four parts:1. IntroductionThis chapter content mainly summarized the significance on the electrochemistry of redoxproteins and their research progresses, introduced briefly the nanomaterials characteristic, thepreparation and so on, emphatically introduced the nanomaterials modified electrode in biologicalelectrochemistry application.2. Direct electrochemistry of cytochrome c at nanocomposite modified electrodeHydroxyapatite/ carbon nanotube composite materials was synthesized with the help ofultrasonic agitation and modified on the surface of glass carbon electrode. The electrochemicalbehaviors of cytochrome c on this modified electrode were studied. The results showed thatcytochrome c exhibited good current responses with the linear ranging from 6.0×10^-7 to 5.0×10^-5mol/L, the calculated detection limits was 3.0×10^-7 mol/L at S/N=3.3. Direct electron transfer of redox proteins at attapulgite modified electrodeNatural nano-structure attapulgite clay was purified by mechanical stir with the aid of ultrasonic wave and its structure and morphology was investigated by XRD and transmission electronmicroscopy (TEM). Hemoglobin and Cytochrome c were immobilized on attapulgite modified glassycarbon electrode respectively. The interaction between redox protein and attapulgite clay wasexamined by using UV-vis spectroscopy and electrochemical methods. The direct electron transfer ofthe immobilized proteins exhibited a pair of redox peaks in 0.1mol/L pH 7.0 PBS. The immobilizedboth Hb and Cyt c displayed a high affinity and sensitivity to H₂O₂, which indicated that ATP is agood matrix for protein immobilization and preparation of the third generation biosensors withoutusing any mediators.4. Direct electrochemistry of Cytochrome c at Potato Dietary Fiber modified electrodePotato dietary fibre (PDF) was prepared by steam explosion and oxidation with the wasteresidue of potatoes, the structure and morphology of potato dietary fibre were investigated by IR,SEM. After a series of physical and chemical treatments, the long chains of galactan in potato residuechanged into short chains and the original block forms became ruleless net-bedded structure, thealdehyde of galactose was changed into carboxyl. PDF has characteristics of larger ratio specificsurface area and thermodynamics stabilization. The Potato Dietaty Fiber and Polyvinyl Alcohol weremodified on the surface of glassy carbon electrode and a novel electrochemical sensor was developed.The direct electron transfer of Cytochrome c immobilized on this modified electrode was studied.The interactions between Cytochrome c and Potato Dietary Fiber were investigated by UV-Vis andelectrochemical methods. A new biosensor of hydrogen peroxide was constructed with linearcalibration range of 8.0×10^-6～2.4×10^-4 mol/L and the detection limit of 4.0×10^-4 mol/L.