School of Materials Science and Engineering, Nanyang Technological University, Singapore.
Talanta. 2010 Sep 15;82(4):1344-8. doi: 10.1016/j.talanta.2010.06.061. Epub 2010 Jul 24.
A novel electrochemical sensing system for direct electrochemistry-based hydrogen peroxide biosensor was developed that relied on the virtues of excellent biocompatibility, conductivity and high sensitivity to the local perturbations of single-layer graphene nanoplatelet (SLGnP). To demonstrate the concept, the horseradish peroxidase (HRP) enzyme was selected as a model to form the SLGnP-TPA (tetrasodium 1,3,6,8-pyrenetetrasulfonic acid)-HRP composite film. The single-layer graphene composite film displayed a pair of well-defined and good reversible cyclic voltammetric peak for Fe(III)/Fe(II) redox couple of HRP, reflecting the enhancement for the direct electron transfer between the enzyme and the electrode surface. Analysis using electrochemical impedance spectroscopy (EIS) revealed that electrostatic attractions existed between graphene monolayers and enzyme molecules. The intimate graphene and enzyme interaction was also observed using scanning electron microscopy (SEM), which resulted in the special properties of the composite film. Ultraviolet visible spectroscopy (UV-vis) indicated the enzyme in the composite film retained its secondary structure similar to the native state. The composite film demonstrated excellent electrochemical responses for the electrocatalytic reduction of hydrogen peroxide (H(2)O(2)), thus suggesting its great potential applications in direct electrochemistry-based biosensors.
开发了一种新型电化学传感系统，用于基于直接电化学的过氧化氢生物传感器，该系统依赖于单层石墨烯纳米片（SLGnP）的优异生物相容性、导电性和对单层石墨烯纳米片局部扰动的高灵敏度。为了验证这一概念，选择辣根过氧化物酶（HRP）作为模型，形成 SLGnP-TPA（四磺酸钠 1,3,6,8-苝四磺酸）-HRP 复合膜。单层石墨烯复合膜显示出一对定义良好且良好的 HRP 的 Fe(III)/Fe(II)氧化还原对可逆循环伏安峰，反映了酶与电极表面之间直接电子转移的增强。电化学阻抗谱（EIS）分析表明，石墨烯单层和酶分子之间存在静电吸引。扫描电子显微镜（SEM）也观察到石墨烯和酶的紧密相互作用，这导致了复合膜的特殊性质。紫外可见光谱（UV-vis）表明，复合膜中的酶保留了与其天然状态相似的二级结构。复合膜对过氧化氢（H(2)O(2)）的电催化还原表现出优异的电化学响应，因此表明其在基于直接电化学的生物传感器中有很大的应用潜力。
