羧基化多壁碳纳米管修饰电极循环伏安法测定过氧化氢

目的：研究用羧基化多壁碳纳米管修饰电极伏安法测定过氧化氢的浓度。方法：采用涂布法制成羧基化多壁碳纳米管修饰电极;在pH=7.0KH2PO4-Na2HPO4缓冲溶液中,采用该修饰电极伏安法测定H2O2。结果：该修饰电极对H2O2有着显著的电催化作用,与裸玻碳电极相比,其灵敏度大大提高,在1.2×10-6～1.0×10^-3mol/L浓度范围内,过氧化氢的氧化峰电流与其浓度呈良好的线性关系,检测限为3.1×10^-7mol/L,将该修饰电极用于医用过氧化氢的测定,相对平均偏差为1.2%,平均回收率为97.6%,结果满意。结论：该修饰电极响应快,灵敏度高,稳定性好,寿命长,适合于具有电活性生物分子的测定。

Determination of hydrogen peroxide by voltammetry with multi-wall carbon nanotubes functionalized with carboxylic group modified electrode

Objective： To study a quantitative method for determination of hydrogen peroxide （H2O2） by voltammetry with multi-wall carbon nanotubes functionalized with carboxylic group modified electrode （CME）. Method： The CME was fabricated, which based on the immobilization of multi-wall carbon nanotubes functionalized with carboxylic group. In a medium of KH2PO4-Na2HPO4 buffer solution with pH=7.0, the CME was utilized for determination of H2O2 by voltammetry. Results： The CME exhibited efficiently catalytic oxidation for H2O2. Compared with the bare glass carbon electrode, the CME could increase the sensitivity for the determination of H2O2. The oxidation currents were linear for H2O2 in the range of 1.2×10^-6～ 1.0×10^-3 mol/L, and the detection limit was calculated to be 3.1×10^-7mol/L. The CME had been applied to assess the contents of H2O2 with RSD 1.2% and average recovery rate 97.8%. Conclusion： The CME shows high sensitivity, stability and long-life, and is suitable for the determination of biologic molecules with electrical activity.