Study on Atomically Ordered Surfaces of Functional Electrodes for Electron Transfer Reactions of Metalloproteins

在本研究中，利用金单晶电极表面研究了金属蛋白电子转移反应修饰电极的表面功能。单晶电极表面的制备与表征：采用真空蒸发法和火焰退火淬火法制备了金单晶电极表面，并通过STM/AFM和电化学测量对其表面进行了表征。金属蛋白电子转移反应的功能电极表面：(1)采用STM、表面增强红外吸收光谱（SEIRAS）和电化学还原脱附技术研究了用于细胞色素c电化学的修饰金单晶电极的表面结构。例如，在Au（11）表面，吸附的4-吡啶硫醇（4-PySH）在相邻的两个4-PySH的相互作用下呈现出p（5*<平方根> 3r - 30o <s:1>）结构的矩形单元胞，而2…More -PySH修饰的电极则呈现出p(4*<平方根> 7r - 40o结构。2-PySH结构不形成二聚体，表明2-PySH可以同时吸附硫酸盐S和吡啶N原子。(2)利用In203电极的高亲水性sinch面，发现天然肌红蛋白和重组肌红蛋白的生物功能和电子传递动力学与血红素结构密切相关，如血红素的卟啉主链、氧化还原中心的金属离子类型、配位结构等。用硫醇修饰单晶金电极表面：在硫醇修饰剂溶液中发现极少量（约1%）的硫化物杂质会使修饰后的表面结构在某些情况下变得复杂。然而，改性表面的结构在很大程度上受改性过程的热力学和动力学方面的控制。硫醇吸附在电极表面的还原解吸峰电位是预测修饰表面结构的一个很好的指标。硫醇改性表面的电化学制备也得到了发展。少

In the present study, surface functions of modified electrodes for electron transfer reactions of metalloproteins have been examined by using gold single crystal electrode surfaces.1. Preparation and characterization of single crystal electrode surfaces :Gold single cryatal surfaces were prepared by both vacuum evaporation and flame-annealing-quenching methods, and their surfaces were characterized by STM/AFM and electrochemical measurements as a function of preparation conditions.2. Functional electrode surfaces for electron transfer reactions of metalloproteins :(1) Surface structures of modified Au single crystal electrodes for cytochrome c electrochemistry were studied by STM, surface-enhanced IR absorption spectroscopy (SEIRAS) and the electrochemical reductive desorption technique. On the Au(1 11) surface, for example, adsorbed 4-pyridinethiol (4-PySH) showed the rectangular unit cell of p(5*<square root>3R-3Oﾟ) structure with an interaction of two neighboring 4-PySH, while the 2 … More -PySH modified electrode showed a p(4*<square root>7R-4O.9ﾟ) structure with no dimer formation, suggesting that 2-PySH adsorbs at both thiolate S and pyridine N atoms.(2) Using highly hydrophilic sin-face of In203 electrodes, biological functions and electron transfer kinetics of native and reconstituted myoglobins were found to be related very much to the heme structure, such as the porphyrin backbone of the heme, type of metal ion of the redox center, coordination structure etc.3. Modification with thiols on single crystal gold electrode surfaces :A very small amount (ca. 1%) of sulfide impurity in a thiol modifier solution was found to make the modified surface structure complicated in some cases. However, the structure of modified surface was very much controlled by thermodynamic and kinetic aspects of the modification processes. The reductive desorption peak potentials of thiols adsorbed on the electrode surfaces were found to be used as an excellent measure for predicting the structures of the modified surfaces. Electrochemical fabrication for the thiol modified surface has also developed. Less