甲基纤维素膜固载肌红蛋白的电化学和电催化

Direct Electrochemistry and Electrocatalysis of Myoglobin Entrapped in Methyl Cellulose Hydrogel Films

用甲基纤维素(MC)将肌红蛋白(Mb)固载于热裂解石墨电极表面, 制备了Mb MC膜修饰电极. 修饰膜中的Mb与电极直接传递电子. 在磷酸盐缓冲溶液(PBS)中循环伏安扫描可得到一对可逆的Mb辅基血红素Fe(Ⅲ) / Fe(Ⅱ) 电对氧化还原峰, 式电势为-0.298 V(vs SCE). 式电势随PBS的 pH值增加而负移且成线性关系, 说明 Mb的电子传递过程伴随有质子的转移. 最后探讨了该修饰电极对O2,H2O2 和NO的电催化性质.

Myoglobin was immobilized on edge-plane pyrolytic graphite (EPG) electrodes by Methyl Cellulose hydrogel. The protein entrapped in the Methyl Cellulose film undergoes fast direct electron-transfer reactions with the formal potential (E^(0′)) of -0. 298 V(vs SCE), corresponding to Fe~Ⅲ+e^-→Fe~Ⅱ, the E^(0′)s are linearly dependent on solution pH, indicating that the electron transfer was proton-coupled. The mechanisms for catalytic reduction of oxygen, hydrogen peroxide and nitric oxide by myoglobin entrapped in Methyl Cellulose hydrogel were also explored.