Study On Electrochemical Behaviors Of　β-Cyclodextrin And Its Derivatives And Nano Carbon Materials

Electrochemical analysis method is attributed chemical changes to electrochemicalreactions. Usually, the potential, current or electric quality of the reaction system is used asmeasurement of the reaction in this method. And the method has some advantages such assimple, high sensitivity and good real-time. The mixture of β-cyclodextrin (β-CD) and nanocarbon materials has good conductivity, stability and biocompatibility. It can be well fixedinto various substances without adding any crosslinking agent. At present, such complexsystem is mainly used to design various biological electrochemical sensors and improvebiological activity and optoelectronics properties of some devices. In this thesis, some specificmethods were used to modify CNTs、graphene and β-cyclodextrins in order to improve theirsolubility and dispersion, as well as improve the electrochemical properties of CNTs、graphene and β-cyclodextrins. The functionalized CNTs、graphene and β-cyclodextrins areapplied to the electrochemical performance determination of some biomacromolecules. Theelectrochemical behaviors of these biological macromolecules were investigated and thecontent of these biological macromolecules were determined. More effective methods forseparation and testing were explored. The mainly contents of the thesis are as follows:1. The electrocatalytic behaviors of dopamine (DA) and ascorbic acid (AA) inamino-β-cyclodextrin (β-CD-NH2)/graphene/ferrocene modified electrode were studied.Firstly, the amino-β-cyclodextrins/graphene composite was prepared and the inclusioncomplex of amino-β-cyclodextrins and ferrocene(Fc) was combined with graphene. Then theywere used drop-coated method to prepare modified electrode for determination of DA and AA.Results showed that the electrode modified with amino-β-cyclodextrin/graphene/ferrocenecan effectively promote electron transfer rate of these two biological macromolecules in theelectrode surface and perform excellent electrocatalysis in the redox behaviors of the twobiomacromolecules in bodies, the DA and AA in coexistence conditions were separated and detected.2. Carboxyl groups were grafted to the surface of single-walled carbon nanotubes(SWCNTs), then carboxylic SWCNTs were scattered in amino-β-cyclodextrin/ferrocenesolution by sonication. Subsequently, the modified electrode was prepared with drop-coatedmethod, the electrochemical behaviors of DA were studied in different conditions utilizing themodified electrode via cyclic voltammetry method. The results indicated that theβ-CD-NH2/SWCNTs-COOH/Fc modified electrode can effectively promote electronstransfer rate of DA in the electrode surface and perform excellent electrocatalysis in the redoxbehaviors of DA.3. The electrochemical behaiors of nicotine and catechol on the carboxylicβ-cyclodextrin/graphene/ferrocene modified glassy carbon electrode has been investigated.The stability of graphene in the electrodes was reinforced by carboxyl-β-cyclodextrins/graphene complexes via chemical method. Furthermore, the modified glassy carbon electrodewas applied to the electrochemical behaviors reserch of nicotine and catechol in differentconditions utilizing cyclic voltammetry method. The results showed that the modifiedelectrode indicated excellent catalytic properties and the method indicated good stability, highsensitivity in the electrochemical determination of nicotine and catechol.4. Aim to improve the electrochemical properties of electrode, the magnetic grapheneswere prepared and used to modify the naked glass carbon elecreode. Finally, theelectrocatalytic property of carboxyl-β-cyclodextrins/graphene-Fe3O4composite filmmodified electrode was investigated. It is showed that obvious catalytic properties, goodstability, the electrode has a long lifetime, it can be applied in real-detection.5. Firstly, the sulphur-β-cyclodextrins was synthesized for improving the solubilities ofβ-cyclodextrins. Then, the functionlized β-cyclodextrins was combined with graphene andused to modify gold electrode. Ultimately, the modified electrode was applied to determinethe electrochemical behaviors of DA and AA. The results showed that the modified goldelectrode illustrated higher sensitivity than modified glass carbon electrode. Moreover, themodified gold electrode illustrated good electrocatalystical properties.