辣根过氧化物酶在海藻酸钠水凝胶中的电化学和电催化特性

Electrochemical Characteristics and Electrocatalysis Behavior of Horseradish Peroxidase Entrapped in Sodium Alginate Hydrogel Films

用海藻酸钠(SA)将辣根过氧化物酶(HRP)固定到热裂解石墨电极表面,制备了HRP-SA膜修饰电极。研究结果表明,包埋在SA膜中的辣根过氧化物酶可与电极直接传递电子,在磷酸盐缓冲溶液和磷酸盐/乙醇混合溶液中均可得到1对辣根过氧化物酶辅基血红素Fe(Ⅲ)/Fe(Ⅱ)电对的可逆氧化还原峰。其式电势随溶液pH值增加而负移,呈线性关系,这说明辣根过氧化物酶的电子传递过程伴随有质子的转移。考察了HRP-SA膜修饰电极对O2气、H2O2、NO和六氯乙烷的电催化性质。

A stable enzyme-modified electrode was made by immobilizing horseradish peroxidase （HRP） on edge-plane pyrolytic graphite（EPG） electrode with sodium alginate hydrogel, The entrapped HRP underwent a fast direct electron-transfer reaction in both phosphate buffer and phosphate-ethanol buffer. The formal poten- tial（ -0. 364 V vs SCE） indicates the redox of HRPFe（Ⅲ）/（Ⅱ） couple. The E°′ is linearly dependent on solution pH, suggesting that electron transfer is proton-coupled. The catalytic reductions of oxygen, hydrogen peroxide, nitric oxide and the dehalogenation of hexachloroethane by HRP were also explored.