固定化肌红蛋白的电化学和电催化性能研究

Electrochemistry and Enzymatic Catalysis of Immobilized Myoglobin

用海藻酸钠(Sodium Alginate,SA)将肌红蛋白(Mb)固定在热裂解石墨电极表面,制备了Mb-SA膜修饰电极。包埋在SA膜中的Mb在磷酸盐缓冲溶液(PBS)和乙醇混合溶液中与电极直接传递电子,得到一对对称的Mb辅基血红素Fe(III)/Fe(II)电对的氧化还原峰,式电势为-0.339V(vs SCE)。式电势随缓冲溶液pH增加而负移且成线性关系,直线斜率为-47.0mV/pH,说明肌红蛋白的电子传递过程伴随有质子的转移。并研究了Mb-SA膜修饰电极在水-乙醇混合溶液中催化还原H2O2和NO,该修饰电极可用于H2O2和NO2-的定量检测。

Myoglobin was immobilized on edge-plane pyrolytic graphite（EPG） electrodes by sodium alginate hydrogel.The protein entrapped in the sodium alginate film in aqueous-ethanol solvent mixture underwent fast direct electron-transfer reaction with the formal potential（E0＇） of-0.339V（vs SCE）,corresponding to Fe（III） / Fe（II）.The E0＇s was linearly dependent on buffer solution pH with the slope value of-47.0mV/pH,indicating that the electron transfer was proton-coupled.The catalytic reduction of hydrogen peroxide and nitric oxide by myoglobin entrapped in sodium alginate hydrogel in aqueous-ethanol solvent mixture was also studied.