血红蛋白在室温离子液．壳聚糖．碳纳米管复合材料修饰玻碳电极上的直接电化学行为

制备了1-丁基-3-甲基咪唑六氟磷酸盐离子液（BMIM]PR），壳聚糖（CS）-多壁碳纳米管（MWNT）复合材料修饰的玻碳电极（BMIM]PF6,／CS-MWNT／GCE），并用于血红蛋白（Hb）的固定及直接电化学研究．电化学实验表明，BMIM]PF6／CS-MWNT复合膜能大大提高电极的有效表面积及电子传导性能．在pH7．0的磷酸盐缓冲液（PBS）中，Hb在修饰电极表面呈现一对可逆的氧化还原峰，对应于血红蛋白辅基血红素中Fe（Ⅲ）／Fe（Ⅱ）的氧化还原电对，式量电位（Eθ）为．0．451V，传递系数（n）和直接电子转移的速率常数（k）分别为0．427和0．065s^-1．在pH5．0-pH9．0的范围内，式量电位和pH值有良好的线性关系，其斜率为-40．6mV／pH，这表明Hb一个电子的传递伴随着一个质子的转移．同时，该修饰电极对H202表现出良好的电催化性能，构造了一种具有良好稳定性和重现性的新型第三代生物传感器．

Direct Electrochemistry of Hemoglobin on [BMIM]PF6-Chitosan- Carbon Nanotube Composite Material Modified Glassy Carbon Electrode

In this study, a nano-composite material consisted of muti-walled carbon nanotube （MWNT）, chitosan （CS） and 1-butyl-3-methylimidazolium hexafluoro-phosphate （BMIM]PF6） was prepared and used for the immobilization of hemoglobin （Hb）. Electrochemical characterization experiments revealed that BMIM]PF6/CS-MWNT greatly increasel the effective surface area and electron conductivity of the interface. Based on these positive properties, a pair of stable and quasi-reversible peaks for the Hb-Fe（Ⅲ）/Fe（Ⅱ） redox couple with the apparent formal potential （E^θ） at -0.451 V were obtained in pH 7.0 phosphate butter solution （PBS）, indicating the realization of the direct electrochemistry of Hb by the composite material. The electron transfer rate constant （ks） and electron transfer coefficient （a） were calculated as 0.065 s^-1 and 0.427, respectively. The E^θ of Hb shifted linearly to the increase of buffer pH with a slope of -40.6 mV/pH, indicating that one electron transferred was accompanied with one proton transportation. The immobilized Hh showed excellent eletrocatalytic responses to the reduction of H2O2, and the related parameters were calculated. Based on the fabricated bioelectrode, a new third-generation biosensor was constructed with good stability and reproducibility.