MWNTs与GNPs—CHIT修饰的过氧化氢生物传感器

在玻碳电极（GCE）上自组装一层多壁碳纳米管（MWNTs），构建负电荷的界面，然后，静电吸附一层阳离子电子媒介体硫堇（Thi），再由共价键作用自组装一层纳米金（GNPs），壳聚糖（CHIT）混合溶液的复合薄膜，通过静电吸附辣根过氧化物酶（HRP）制得过氧化氢（H2O2）生物传感器。采用循环伏安法和计时电流法考察了该生物传感器的电化学性质，并研究了该修饰电极对H2O2的催化还原作用。生物传感器的响应电流与H2O2浓度在8．2×10^-6～1．1×10^-3mol／L范围内呈现线性关系，检出限为5．8×10^-7mol／L，达到95％稳态响应时间约为15s。将此生物传感器用于H2O2的检测，结果令人满意。

Hydrogen peroxide biosensor based on MWNTs and GNPs-CHIT

Multi-walled nanotubes(MWNTs) is self-assembled onto the coated glassy carbon elecrtode(GCE) to form a negative-charge surface. Cationic dye-thionine (Thi) is linked by electrostatic adsorption as an electron transfer mediator. Next the mixture of gold nanoparticles ( GNPs) and chitosan ( CHIT) is assembled on the electrode by covalent bond. The positively charged horseradish peroxidase is successfully immobilized on the GNPs surface. The electrocataltyic behavior of the modified electrode to H_2O_2 is investigated by cyclic voltammetry and chronoamperometry. The experiments show that the modified electrode has excellent electrocatalytic activity for the detection of H2_O_2. The linear range of this biosensor is 8.2 ×10~(-6)-1.1 ×10~(-3) mol/L with a detection limit of 5.8 ×10~(-7) mol/L. The response time achieved 95 % steady state is about 15 s. The biosensor is applied for deteetion of H_2 O_2 , and the results are satisfied.