碳纳米管组装电极上计时电流法测定辣根过氧化物酶的研究

以多壁碳纳米管修饰玻碳电极为工作电极，研究了辣根过氧化物酶（HRP）一对苯二酚（HQ）-H2O2体系的电化学催化行为。比较碳纳米管修饰玻碳电极和玻碳电极，峰电位从64mV（vs．SCE）前移至116mV，催化电流提高了10倍。对工作电位、介质pH、H2O2和HQ浓度进行了选择。在优化的实验条件下，采用计时电流法测定HRP的线性范围为5．0×10-10～1．0×10-10g／mL。检出限为2．5x1×10-10g／mL。该法具有电极制作简单和灵敏度高等优点。

Chronoamperometric Determination of Horseradish Peroxidase at a Glassy Carbon Electrode Modified with Multiwall Carbon Nanotubes

A simple and highly sensitive amperometric method for the determination of horseradish peroxidase （HRP） has been developed at a glassy carbon electrode modified with multiwall carbon nanotubes （MWNT）. It was found that the catalytic reduction currents of quinine generated in the reac- tion of hydroquinone with hydrogen peroxide in the presence of horseradish peroxidas （HRP） was greatly enhanced at MWNT modified electrode in 0.05 mol/L phosphate buffer solution （pH=7.0）. The reduction peak of hydroquinone appeared at 116 mV（ vs. SCE） and 64 mV at MWNT modified glassy carbon electrode and glassy carbon electrode, respectively. In the optimized solution of 0.05 mol/L PBS （pH=7.0） containing 2×103 moFL H202 and 1.5 ×10-3 moFL HQ, the catalytic reduction currents on a MWNT-modified glassy carbon electrode at an applied potential of 30 mV is linear over a range from 5.0×10-10 - 1.0×10-8 g/mL HRP with the detection limit of 2.5×10-10g/mL HRP.