The Study Of Electrochemistry And In Vivo Analysis Based On The Principle Of Closed Bipolar Electrode

Bipolar electrochemistry is a new electrochemical research method which used a bipolar electrode?BPE? as working electrode that the redox reaction occurs at both of ends of the electrode. And the bipolar electrochemistry includes two types of systems called open or closed bipolar electrochemical system, respectively. In this paper, we focused on the closed bipolar system. We provided a novel and efficient method for the detecting of the neurotransmitter or active molecules?such as dopamine, ascorbic acid? in vivo based on the principle of the closed bipolar electrochemistry. Detail:?1? In order to learn more about the closed bipolar system, we studied the influencing factors of the half-wave potential in the system including the concentrations of the electrolyte solution and the length of the electrodes. And we found that the half-wave potential shift negatively when the concentration of the electrolyte or the length of the electrodes decreased. Then we choose the best size of the electrodes and the most suitable concentration of the electrolyte solution?K₃Fe?CN?₆? to prepare the cylindrical carbon fiber electrodes?CFEs? backfilled with the solution of K₃Fe?CN?₆ for the detecting of dopamine in mouse's brain. We compared the stability, sensitivity and the half-wave potential of the CFEs filled of K₃Fe?CN?₆ with the CFEs filled of KCl or Ru?NH3?6Cl3, and the result shows that the CFEs backfilled with K₃Fe?CN?₆ had the highest stability and the smallest half-wave potential?which means the smallest damage to animals? when they are used in vivo to detect catecholamines.?2? Based on the principle of the closed bipolar electrode and made some modified, we construct a novel structure of the battery. When we removed the voltage applied on the two driving electrodes of the closed bipolar system, the oxidation or reduction reaction took place spontaneously on the two sides of the electrode materials, respectively, and there would be potential difference between the two reactions. By this design, a self-generation battery can be constructed, the voltage and power can be output through the two driving electrodes. Under this principle, we have studied the performance of four batteries: H₂-O₂, K₄Fe?CN?₆-O₂, K₃Fe?CN?₆-Fc?COOH?2, and K₃Fe?CN?₆-DA, we found they all have good and stable output.?3? Based on principle of the modified closed bipolar electrode system, we prepared a miniature biosensor for the detecting of ascorbic acid in vivo. The working electrode is a CFE backfilled with the solution of KCl containing K₃Fe?CN?₆, and the surface of the CFE is modified by multi-wall carbon nanotubes to improve the stability and selectivivty of the electrode. We used this biosensor to detect the release of the ascorbic acid in vivo with high stability and selectivity.