辣根过氧化物酶/多壁碳纳米管修饰铂电极生物传感器用于过氧化氢的循环伏安测定

CV Determination of Hydrogen Peroxide Using a Biosensor of Horseradish Peroxidase/Multi-walled Carbon Nanotube Modified Platinum Electrode

将1mg多壁碳纳米管(MWCNT's)分散在5mL的0.5g·L^(-1)壳聚糖溶液中后,滴涂在铂电极表面,制得多壁碳纳米管修饰电极。将上述修饰电极在辣根过氧化物酶(HRP)溶液中浸泡8h,在MWCNT's修饰电极表面静电吸附辣根过氧化物酶,制成过氧化氢生物传感器,用于过氧化氢的测定。试验结果表明:在pH 6.0的磷酸盐缓冲溶液中,HRP/MWCNT's修饰电极对过氧化氢具有明显的电催化还原作用,过氧化氢的浓度在3.5×10^(-5)～9.0×10^(-3)mol·L^(-1)范围内与其还原峰电流呈线性关系,检出限(3S/N)为2.4×10^(-5)mol·L^(-1)。用标准加入法作回收试验,回收率在96.0%～101.8%之间。

One mg of multi-walled carbon nanotube （MWCNT＇ s） was dispersed in 5 mL of 0. 5 g·L^-1 chitosan and dropped onto the surface of Pt electrode. The MWCNT＇s modified Pt electrode prepared as described above was immersed in horseradish peroxidase （HRP） solution for 8 h, and the HRP was adsorbed electrostatieally on the surface of MWCNT＇s modified electrode. Thus the hydrogen peroxide biosensor was prepared and ready for use in determination of hydrogen peroxide. It was found that in a phosphate buffer solution of pH 6. 0, the reduction of hydrogen peroxide at the modified electrode was remarkably catalyzed. Cyclic vohammetric determination of hydrogen peroxide was performed in the linearity range of 3. 5 ×10^-5 to 9.0 ×10^-3 mol·L^-1 in respective to the value of reductive peak current. Value of detection limit （3S/N） found was 2. 4 ×10^-2 mol·L^-1. Test for recovery was made by standard addition method, and values of recovery found were in the range of 96. 0%- 101.8%.