Electron Transfer Of Biomolecules At Nano-materials Modified Interface

The electron transfer among the biomolecules is an important reaction in implementing the biofunctions. Electrochemical method is applied widely in life science researches due to its advantages of rapid, simple, lower consume, high sensitivity, real time and real place examination. It can be used to research the electron transfer process among the biomolecules, which not only can obtain the basic thermodynamics and dynamics parameters, but also can show the electron transfer mechanism.Carbon nanotubes (CNTs) as one kind of new nano-materials have attracted widely attention in electrochemical sensors'studies for their perfect electron-transfer capacity and bio-compatibility. Quantum dots (QDs) have attracted considerable attention in the past decades because they have been used as luminescent probes in biology, medicine and more recently in bioanalytics. At the same time, their quantum size effect has been applied for research in other aeras.In this thesis, the method by drying/adsorption was used to prepare DNA and CNTs adsorptively modified electrodes, and adopted electrochemical to research the electrochemical behaviors of molecules, and the main contents and results are summarized as follows:(1) The multi-wall carbon nanotubes (MWNTs)-QDs composite modified glassy carbon electrode (GCE) was prepared. The complex was characterized by the transmission electron microscope (TEM). The area of the electrode was calculated. (2) The electron transfer of levodopa at MWNTs and QDs modified GCE (MWNTs-QDs/GCE) was studied by cyclic voltammetry (CV) and chronocoulometry (CC). It was found that its electrochemical behavior was a two-charge-two-proton process. The modified electrode had high electrocatalytic activity for levodopa with standard heterogeneous rate constant of 0.595 cm s-1, which was greatly increased compared with bare GCE and individual MWNTs modified GCE. The better electrocatalytic activity for levodopa at MWNTs-QDs/GCE may due to the synergistic effect between MWNTs and QDs. This result provides a novel way in the research of biomicromolecule at nano-size.