琼脂糖固载辣根过氧化物酶的直接电化学行为研究

Direct Electrochemical Behavior of Horseradish Peroxidase Entrapped in Agarose Hydrogel Films

用琼脂糖将辣根过氧化物酶(HRP)固定到玻碳电极(GCE)表面,制备了HRP-琼脂糖膜修饰电极。研究发现包埋在琼脂糖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缓冲溶液/乙醇混合液中均可得到一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,式电势分别为-0.392V(vs SCE)和-0.412V(vs SCE)。式电势随缓冲溶液pH值增加而负移,且呈线性关系,直线斜率为-56.0mV/pH。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。

Horseradish peroxidase was immobilized on glassy carbon electrode（GCE）surface by agarose hydrogel.Horseradish peroxidase entrapped in the agarose film in phosphate buffer solution and phosphate buffer ethanol mixed solvent undergoes fast direct electron-transfer reactions with the formal potential（E01）of-0.392V（vs SCE）and-0.412V（vs SCE）respectively,corresponding to Fe3＋＋e-→Fe2＋.The E01 is linearly dependent on pH of the buffer solution with the slope value of-56.0mV/pH,indicating that the electron transfer is proton-coupled.