铁蛋白在单壁碳纳米管修饰电极上的直接电化学过程研究

Electrochemical Study of Ferritin on SWNTs-CTAB Modified Electrode

采用溴化十六烷基三甲基铵(CTAB)分散的单壁碳纳米管(SWNTs)将铁蛋白(Ft)固定在玻碳电极(GCE)表面,制备了铁蛋白-单壁碳纳米管-溴化十六烷基三甲基铵膜修饰玻碳电极(Ft-SWNTs-CTAB/GCE)。透射电子显微镜和原子力显微镜用于该膜的形貌表征,红外反射吸收光谱表明复合膜中的Ft保持原有的天然结构。采用循环伏安(CV)法研究了Ft在此修饰电极上的直接电化学和Ft中铁储存和铁释放的机理:在电化学还原过程中,Fe3+从蛋白质中还原出来,并在电化学氧化过程中重新进入到蛋白质内,CV曲线上有较好的氧化还原峰,峰电流较大,响应信号较好。利用去铁铁蛋白进行对比实验,进一步证实了Ft在SWNTs-CTAB修饰电极上的铁储存和铁释放过程。

A ferritin-single walled carbon nanotube-hexadecyl trimethyl ammonium bromide （ferritin-SWNTs- CTAB ） film modified glassy carbon electrode had been prepared. Transmission electron microscopy and atomic force microscopy were used to characterize the morphology of films. Reflectance absorption infrared showed that the ferritin retained their native structure in SWNTs-CTAB film. The process of uptake and release of iron by ferritin was studied by cyclic voltammetry： in the cathodic scan process, the Fe（~ in the ferritin core was reduced to Fe（ll） and released, in the anodic scan process, the Fe（lI） was oxidased to Fe（m） and uptake to ferritin core again. A control experiment was designed which entailed forming a film from an authentic apoferritin and observed how apoferritin to behave under similar iron uptake conditions. The control experiment further confirmated the uptake and release process of iron in ferritin.