The Preparation And Its Application Of Electrode Modified With Ionic Liquid And Sol-gel Or KGM

The purpose of this thesis is to study a good immobilize technique for biology. At first, Hemoglobin (Hb) was used as a study system. The Hb has been immobilized onto the surface of glassy carbon (GC) electrode with ionic liquid polymer and obtained experimental conditions was used for immobilize chloroperoxidase (CPO), which had been little researched. These results could make some experience of CPO modified electrode preparation and theoretical study basic on application of CPO.The thesis includes the following parts:1. Study on electrochemical behavior of Hemoglobin (Hb) at ionic liquid polymer modified electrodeThe ionic liquid polymer solution was dropped onto the GC electrode surface for immobilization of Hb. The cyclic voltammetry measurements showed that the direct electron transfer of Hb at the electrode modified with ionic liquid polymer was observed, and it was a quasi-reversible electrochemical redox reaction controlled by diffusion. This work developed an easy way for enzymes immobilization and fabrication of amperometric biosensors.2. Study on electrochemical behavior of Hb at ionic liquid and Sol-gel modified electrodeA new technique of Hb immobilized with sol-gel and ionic liquid by layer by layer coatings was reported. The cyclic voltammetry results show that Hb immobilized at the modified electrode can undergo the direct electron transfer, the formal potential (E0') shifted negatively with the solution pH increased in the range from 4 to 9. The liner relationship of the E0'versus pH with a slope 50.95 mV/pH demonstrated that one proton transfer is coupled to each electron transfer in the electrochemical redox reaction of Hb. The drying condition have been investigated. The results showed that the lower temperature and higher humidity can avoid the cracking of sol-gel films. 3. Study on electrochemical behavior of Hb at ionic liquid and konjac glucomannan (KGM) modified electrodeIn this work, the sol-gel films is replaced by KGM film. The direct electron transfer of Hb is clearly observed at the electrode modified with ionic liquid and KGM. The cyclic voltammetry results suggested that the immobilized heme-proteins exhibit surface-controlled electrochemical behavior rather than freely diffusing process, in addition, the promotion of different kind of ionic liquid in the electrochemical redoxreaction of Hb was also discussed. The results show that the hydrophilic ionic liquid was better than hydrophobic ionic liquid.4. Study on electrochemical behavior of CPO at ionic liquid and konjac glucomannan (KGM) modified electrode and its applicationsThe chloroperoxidase (CPO) have been immobilized with KGM film and ionic liquid on glassy carbon electrode. The electrochemical behaviors of the immobilized CPO were investigated by cyclic voltammetry. The results showed that CPO was successfully immobilized on the GCE and undergo fast direct electron transfer reactions with the formal potential at -0.3 V and the redox was a process controlled by surface adsorption. The cyclic voltammograms measured in verious pH showed that the formal potential (E0') shifted negatively with the solution increased in the range from 4 to 8. The liner relationship of the E0'versus pH with a slope 43 mV/pH demonstrated that one proton transfer is coupled to each electron transfer in the electrochemical redox reaction of CPO.The catalytic activity of CPO-KGM/RTIL/Nafion/GC modified electrode for electrochemical reduction of O2 and H2O2 have been investigated, and its electrocatalytical mechanism was also discussed briefly. With increasing the concentration of H2O2, the cathodic peak current of CPO increased linearly, which can extend the application of CPO in the H2O2 detection field.