MWNTs与GNPs-CHIT修饰的过氧化氢生物传感器

Hydrogen peroxide biosensor based on MWNTs and GNPs-CHIT

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。

Muhi-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 H2O2 is investigated by cyclic vohammetry and chronoamperometry. The experiments show that the modified electrode has excellent electrocatalytic activity for the detection of H2O2. The linear range of this biosensor is 8.2×10^-6～1.1×10^-3mol/L with a detection limit of 5.8×10^-7mol/L. The response time achieved 95 % steady state is about 15 s. The biosensor is applied for deteetion of H2O2, and the results are satisfied.