基于硫堇/碳纳米管修饰电极的新型过氧化氢电化学传感器

摘要

Based on the synergic effect of multi-walled carbon nanotubes(CNTs) and thionine(Th) , a novel hydrogen peroxide electrode ( HRP/GA - Th/CNTs/GC ) was fabricated by immobilizing horseradish peroxidase( HRP) onto the thionine(Th) /multi-walled carbon nanolubes modified electrode via glutaradehyde( GA) cross-linking. The introduction of CNTs into the electrode is helpful for the further immobilization of Th and the catalysis to H2O2. Furthermore, Th immobilized on CNTs by electrostatic adsorption not only can transfer electrons between the electrode and the redox activity center of the enzyme, but also can enable amine group( NH2) in Th to provide convenience for the immobilization of HRP enzyme via glutaradehyde cross-linking. Additionally, effects of various ex-perimental parameters on H2O2 sensing, including applied potential, pH value and electroactive in-terferent, were investigated. At an optimal potential of - 0. 3 V, the current response of the biosen-sor in phosphate buffer( pH 7. 0) was linear with H2O2 concentration from 5 μmol· L-1 to 40 μmol . L-1 , with a good detection limit (0. 3μmol L-1), a short response time (within 5 s) and a good anti-interferent ability.%基于碳纳米管(CNTs)和硫堇(Th)的协同效应,将辣根过氧化物酶(HRP)通过戊二醛(GA)交联作用固定在硫堇( Th)/CNTs修饰电极上,构造了一种新型酶电极(HRP/GA -Th/CNTs/GC).CNTs静电吸附正电荷的Th,而Th不仅可以促进电极和酶的氧化还原活性中心之间的电子传递,而且能使CNTs氨基(-NH2)功能化,从而利于HRP的固定.基于HRP/GA - Th/CNTs/GC电极的过氧化氢传感器具有较好的传感性能,且检出限低(0.3μmol·L-1)、响应时间短(5s内)、抗干扰能力强.