【作者】 翟自芹；

【导师】 孙伟；

【作者基本信息】 青岛科技大学 ， 无机化学， 2009， 硕士

【摘要】 血红蛋白（Hemoglobin, Hb）是一种血红素蛋白质,是研究氧化还原蛋白质直接电子传递的理想分子。由于氧化还原蛋白质与裸电极很难发生直接电子传递,不同类型的膜修饰电极可以加快电子传递速率。最近几年,纳米粒子由于其独特的物理化学性能而被广泛应用于蛋白质膜修饰电极。室温离子液体由于具有以下特殊性质,如高的导电性、良好的化学和热稳定性、宽的电化学窗口和良好的生物相容性而受到电化学工作者的青睐。本论文结合室温离子液体和纳米材料的特性制备了几种血红蛋白修饰电极,并研究了血红蛋白的电化学和电催化行为。论文主要包括以下内容:1.开展了Hb在离子液体修饰碳糊电极（CILE）上的直接电化学行为研究。通过将碳粉与室温离子液体1-丁基-3-甲基咪唑六氟磷酸盐（BMIMPF6）均匀混合制备了离子液体修饰碳糊电极（CILE）。以上述CILE为基底电极,以壳聚糖（CTS）、Nafion、纳米ZnO、多壁碳纳米管（MWCNT）等为成膜材料,采用层层涂布法制备了不同类型的Hb修饰电极如Nafion/nano-ZnO/Hb/CILE、CTS/Hb/MWCNT/CILE。采用扫描电子显微镜（SEM）、紫外可见吸收光谱、傅立叶变换红外光谱和电化学法对修饰电极的性质进行了研究和表征。考察了Hb在不同修饰膜电极上的直接电化学和电催化行为。实验结果表明,Hb在不同的修饰膜内基本保持了其生物活性,循环伏安扫描出现一对准可逆的氧化还原峰,对Hb的直接电化学行为进行了研究,求解了相关的电化学参数。进一步研究了该修饰电极对三氯乙酸（TCA）的电催化性质,实验结果表明所制备的Hb修饰电极表现出良好的电催化性能。2.开展了Hb在离子液体1-乙基-3-甲基咪唑-四氟硼酸盐（EMIMBF4）、MWCNT修饰的碳糊混合电极中的直接电化学行为研究。将血红蛋白、EMIMBF4、MWCNT以及石墨粉均匀混合,并在表面涂布Nafion得到血红蛋白-碳糊修饰电极（Nafion/Hb-CPE）、血红蛋白-离子液体-碳糊修饰电极（Nafion/Hb-IL-CPE）、血红蛋白-碳纳米管-碳糊修饰电极（Nafion/Hb-MWCNT-CPE）。采用电化学方法和扫描电子显微镜（SEM）对混合在碳糊修饰电极中的血红蛋白（Hb）的性质进行了研究,实现了Hb在碳糊修饰电极中的直接电化学,并根据实验数据求解了相关的电化学参数。进一步研究了三氯乙酸（TCA）、H₂O₂等小分子在修饰电极上的电催化行为。更多还原

【Abstract】 Hemoglobin （Hb） is one kind of heme protein, which can be used as model molecule for the investigation the direct electron transfer of redox proteins. Due to the difficulty of direct electron transfer of redox proteins with the bare working electrode, different kinds of film modified electrodes were devised to accelerate the electron transfer rate. In recent years, nanomaterials had been widely used in fabricating the protein film modified electrodes for their unusual physical and chemical properties. Room temperature ionic liquids （RTILs） have attracted the interests of electrochemist for their specific properties, such as relatively high ionic conductivity, good chemical and thermal stability, wide electrochemical windows and good biocompatibility. In this thesis, we prepared several Hb modified electrodes based on room temperature ionic liquids （RTILs） and unique properties of nanoparticles to investigate the electrochemistry and electrocatalysis of Hb. The thesis can be summarized as follows:1. The carbon ionic liquid electrode （CILE） was prepared for investigation the direct electrochemistry of Hb. The CILE was constructed by mixing graphite powder and 1-butyl-3-methylimidazolium hexafluorophate （BMIMPF6） thoroughly. Hb was immobilized on the surface of CILE with Nafion and nano-ZnO film or chitosan and multi-walled carbon nanotubes （MWCNT） film by step-by-step method. In these modified films, the characteristics of Hb were investigated by scan electron microscopy （SEM）, UV-Vis spectrum, FT-IR and electrochemical methods. The results showed that Hb retained its native structure in these films. A pair of well-defined quasi-reversible redox peak of heme Fe（III）/Fe（II） couple appeared. The electrochemical parameters of Hb in the composite film were further carefully calculated. The Hb modified electrode showed excellent electrocatalytic behaviors to the reduction of trichloroacetic acid （TCA）.2. The direct electrochemistry of Hb in the 1-Ethyl-3-methylimidazolium tetrafluoroborate （EMIMBF4） or MWCNT modified CPE was carefully studied. By mixing Hb with graphite powder, MWCNT and paraffin or EMIMBF4 together with a Nafion film applied on the electrode surface as the protective and immobilization layer, Nafion/Hb-IL-CPE and Nafion/Hb-MWCNT-CPE were prepared and further studied by electrochemical method and scanning electron microscopy （SEM）. Direct electrochemistry of Hb in the carbon paste bioelectrode was successfully achieved. In pH 7.0 phosphate buffer solution （PBS）, a pair of quasi-reversible redox peaks was appeared and the electrochemical parameters were furthur calculated. The Hb modified electrode also showed good electrocatalytic ability to the reduction of TCA and hydrogen peroxide （H₂O₂）.更多还原