Photoelectrochemistry Using Semiconductor Electrodes Modified Chemically with Redox Enzymes

(1)我们研究了真空掺杂MoO_3薄膜在不同化学环境中的光致变色性能，发现经紫外光辐照后的MoO_3薄膜的电致变色性能比未经辐照的样品有所增强。我们还对增强效果进行了额外的实验。对辐照样品的拉曼和电导率测量表明，薄膜已经变得更加结晶和导电的性质。这些观察结果可能与观察到的增强效应有关。(2)利用光波导法，将对醇类敏感的光致变色材料和产醇微生物进行了构建新型微生物传感器的尝试，固定化微生物产生的醇类使材料着色，光波导系统检测吸光度的变化。我们选用WO_3作为光致变色材料，S.酿酒酵母作为微生物，并试图构建葡萄糖传感器。(3)我们尝试对葡萄糖氧化酶和过氧化物酶进行化学修饰，构建葡萄糖和过氧化氢的电流型传感器。通过与基于Os的氧化还原聚合物的静电络合将酶修饰到电极上。我们还尝试将酶传感器用于体内分析或电化学反应的中间产物。所得到的微（过氧化氢）传感器的电流密度和灵敏度是10倍以上的宏电极用相同的方法，这是由于径向扩散的电子到电极表面。

(1) We have investigated the photochromic properties of vacuumeaporated MoO_3 thin films in different chemical environments, and found that UV irradiated MoO_3 thin films showed enhancement in electrochromism comparing to a non-irradiated sample. We have also performed additional experiments on the enhancement effct. Raman and conductivity measurements on the irradiated samples show that the films have become more crystallinity and conductive in nature. These observations may be related to the observed enhancement effect.(2) A trial of constructing a new type of microbial sensor has been studied by, utilizing optical waveguide method, photochromic materials which are sensitive to alcohols, and microbial which produces alcohol, Alcohol, which was produced by immobilized microbials, caused the coloring of the materials, and the change in absorbance was detected by optical waveguide system. We chose WO_3 as a photochromic material and S. cerevisiae as microbial, and tried to construct a glucose sensor.(3) We have tried to modify glucose oxidase and peroxidase chemically and constructed amperometric sensors for glucose and hydrogen peroxide. The enzymes are modified onto the electrode by electrostatic complexing with an Os based redox polymer. We have also tried to miniaturize the enzyme sensor for analyzing in vivo or intermediates of electrochemical reactions. The current density and sensitivity of the resulting micro (hydrogen peroxide) sensor were 10 times higher than in macroelectrodes made with the same method, which is due to radial diffusion of the electron to electrode surface.