HRP-PAMAM-MCNT修饰电极的研制及其在油脂中过氧化物测定中的应用

以自组装方式,将多壁碳纳米管、聚酰胺-胺和辣根过氧化物酶修饰到玻碳电极表面,构建了H2O2生物传感器.研究了影响传感器工作性能的因素,确定了最佳分析条件,即pH值6.8的PBS缓冲溶液,工作电位为-0.15 V.在最佳工作条件下,电极对H2O2快速响应(响应时间<1 s),在9×10-7～1×10-4mol/L范围内,电极的电流响应值与H2O2浓度呈现良好的线性关系,线性回归方程为i(μA)=20.76 C(mmol/L)+0.223 0,R=0.999 0,检出限为5.0×10-7mol/L,电极的电流响应灵敏度为0.247 A mol-1.cm-2.电极应用于食用油脂中过氧化物测定,结果与碘量法一致.

Preparation of HRP -PAMAM-MCNT modified electrode and application of determining peroxide in edible oils

A high sensitive and selective peroxide hydrogen biosensor was prepared by modified with multi-walled carbon nanotubes(MWNTs),polyamidoamine(PAMAM) and horseradish peroxidase(HRP) on to the surface of the glassy carbon electrode by layer-by-layer assembling technique.The factors which influence the characteristic of the biosensor were researched and the optimum conditions were determined.Under the optimum conditions,-0.15 V and PBS pH 6.8,the current response of the biosensor was linearly proportional to H2O2 concentration ranged from 9.0×10-7 mol/L to 1.0×10-4 mol/L with a correlation coefficient of 0.999,and a detection limit of 5.0×10-7 mol/L,a sensitivity of 0.246 A mol-1·cm-2 and a fast response time(less than 1s).The linear regression equation was i(μA) = 20.76C(mmol·L-1) + 0.223 0,R=0.999 0,the limitation was 5.0× 10-7 mol/L,the sensitivity of electric currat in electric currat in electrode was 0.247 A mol-1·cm-2.The method is applied to detect the peroxides in edible oils samples with satisfactory results in agreement with those of the iodometric method.