The Investigation On Electron Transfer Process Of Biological Molecule Of Hydroquinone At The Liquid/Liquid Interface

A liquid/liquid (L/L) interface has been suggested as a simple model for biological membranes. In the last decades, electrochemical investigation at the interface between two immiscible electrolyte solutions (ITIES) has attracted much attention of researcher. The charge (electron and ion) transfer has been considerable as an essential physicalchemical process in life activities. Many important chemical and biological systems (such as chemical sensors, drug release of pharmacology, phase transfer catalysis, simulation of biomembrane) could be investigated at the L/L interface. So it is meaning for studying electron transfer (ET) at the L/L interface and putting forward dynamic theories to realize and understand many important physiological processes, e.g. energy metabolizing, free-radical presenting and disappearing.In this paper, both thin-layer cyclic voltammetry (TLCV) and scanning electrochemical microscope (SECM) were applied to investigate the processes of ET at the L/L interface.There are four parts in this thesis, the main contents are as follows:1. A short review was given on the historical background of electrochemistry of L/L interface. The basic principles of L/L interface and the developing foreground were introduced. The outlined of TLCV and SECM was summarized.Especially, the working-principle, development, calculative theories and the application of the two technologies in L/L interfacial electrochemistry were discussed in detail.2. Combined with SECM, the process of ET of QH2-DMFc system at NB/W interface was investigated by TLCV.The results from the two different approaches showed a reasonable agreement, which not only demonstrated the simplicity and the convenience but also expanded the research region of TLCV.3. SECM was applied to investigate the processes of ET in following two systems at NB/W interface: (1) hydroquinone (QH2, in water)-ferrocene (Fc, in NB) system; (2) hydroquinone (QH2, in water)-decamethylferrocene (DMFc, in NB) system. And the formal rate constants of heterogeneous ET were calculated.The results demonstrated the driving force was dominating factor on the rate of electron transfer. Furthermore, taking ClO4- as common ion, the process of its controlling the potential drop at L/L interface has been studied.4. SECM was applied to investigate the effects of stability of univalent porphyrin zinc on electron transport across the simulative membrane. From the results of our study, we can see that the stability of univalent porphyrin zinc species was a dominating factor of the changing trend of the electron transfer rate across the interface. The calculated results by density-functional theory (DFT) proved that same substituents at different place of porphyrin zinc influenced the thermodynamic energy and MOs orbitals of univalent porphyrin zinc species and the stability changed consequently. In this paper, the dependence of the circumambient composing on the rate constants was also studied and domastrated that it would be effective to control the electron transfer rate in the biologic system.