Sun Yi-Xin, Wang Sheng-Fu
Ministry-of-Education, Key Laboratory for the Synthesis and Application of Organic Functional Molecules, and College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, PR China.
Bioelectrochemistry. 2007 Nov;71(2):172-9. doi: 10.1016/j.bioelechem.2007.04.004. Epub 2007 Apr 21.
Heme proteins were immobilized on glass carbon electrodes by poly (N-isopropylac-yamide-co-3-methacryloxy-propyl-trimethoxysilane) (PNM) and exhibited a pair of well-defined, quasi-reversible cyclic voltammetric peaks at about -0.35 V versus a saturated calomel electrode in pH 7.0 buffer solution, corresponding to hemeFe(III)+e-->hemeFe(II). Some electrochemical parameters were calculated by performing nonlinear regression analysis of square wave voltammetry (SWV) experimental data. The formal potential was linearly dependent on pH, indicating the electron transfer of Fe(III)/Fe(II) redox couple accompanied by the transfer of proton. Ultraviolet visible and Fourier transform infrared spectra suggested that the conformation of proteins in the PNM films retained the essential feature of its native secondary structure. Atomic force microscopy images demonstrated the existence of interaction between heme proteins and PNM. N,N-dimethylformamide (DMF) played an important role in immobilizing proteins and enhancing electron transfer between proteins and electrodes. Electrochemical catalytic reductions of hydrogen peroxide and trichloroacetic acid by proteins entrapped in PNM film were also discussed, showing the potential applicability of the film modified electrodes as a biosensor.
通过聚（N-异丙基丙烯酰胺-co-3-甲基丙烯酰氧基丙基三甲氧基硅烷）（PNM）将血红素蛋白固定在玻碳电极上，在pH 7.0缓冲溶液中，相对于饱和甘汞电极，在约-0.35 V处呈现出一对定义明确的准可逆循环伏安峰，对应于血红素铁（III）+e-->血红素铁（II）。通过对方波伏安法（SWV）实验数据进行非线性回归分析计算了一些电化学参数。形式电位与pH呈线性关系，表明Fe（III）/Fe（II）氧化还原对的电子转移伴随着质子转移。紫外可见光谱和傅里叶变换红外光谱表明，PNM膜中蛋白质的构象保留了其天然二级结构的基本特征。原子力显微镜图像证明了血红素蛋白与PNM之间存在相互作用。N，N-二甲基甲酰胺（DMF）在固定蛋白质和增强蛋白质与电极之间的电子转移方面发挥了重要作用。还讨论了PNM膜中包埋的蛋白质对过氧化氢和三氯乙酸的电化学催化还原，表明膜修饰电极作为生物传感器的潜在适用性。
