Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, College of Chemistry & Chemical Engineering, Northwest Normal University, Lanzhou, PR China.
Colloids Surf B Biointerfaces. 2012 Feb 1;90:62-7. doi: 10.1016/j.colsurfb.2011.09.045. Epub 2011 Oct 4.
Development of a highly sensitive nanostructured electrochemical biosensor based on the integrated assembly of horseradish peroxidase (HRP) and single-walled carbon nanotubes (SWNTs) is described. In this study, we describe the use of a sodium cholate suspension-dialysis method to adsorb the horseradish peroxidase (HRP) onto single-walled carbon nanotubes (SWNTs). We demonstrate that HRP-SWNTs conjugates can be assembled into amperometric biosensors which L-cysteine were assembled on a gold electrode through the covalent bond of S-Au and was used as a substrate for the immobilization of enzymes. Direct electron transfer of HRP is realized at SWNTs, and both anodic and cathodic currents of the redox reaction at the l-cysteine-HRP-SWNTs-modified gold film upon electrocatalysis are amplified. Meanwhile, experimental results reveal that HRP is stably immobilized onto the SWNTs and maintains inherent enzymatic activity toward H(2)O(2). The modified electrode shows high sensitivity toward H(2)O(2). A linear response to hydrogen peroxide measurement is obtained over the range from 1.0×10(-12) to 1.0×10(-11)M and an amperometric detection limit of 2.1×10(-13)M due to its bioelectrocatalytic reduction based on direct electron transfer between gold electrode and the active site of the HRP. The biosensor displays excellent operational, storage stability and highly sensitive. The excellent performance validates the integrated assembly as an attractive sensing element for the development of a new hydrogen peroxide amperometric biosensor.
基于辣根过氧化物酶（HRP）和单壁碳纳米管（SWNTs）的集成组装，开发了一种高灵敏度的纳米结构电化学生物传感器。在本研究中，我们描述了使用胆酸钠悬浮透析法将辣根过氧化物酶（HRP）吸附到单壁碳纳米管（SWNTs）上。我们证明，HRP-SWNTs 缀合物可以组装成安培生物传感器，通过 S-Au 的共价键将 L-半胱氨酸组装在金电极上，并用作酶固定化的底物。HRP 在 SWNTs 上实现了直接电子转移，并且在 l-半胱氨酸-HRP-SWNTs 修饰的金膜上电催化时，氧化还原反应的阳极和阴极电流都得到了放大。同时，实验结果表明，HRP 稳定地固定在 SWNTs 上，并保持对 H（2）O（2）的固有酶活性。修饰电极对 H（2）O（2）表现出高灵敏度。由于基于金电极和 HRP 的活性位点之间的直接电子转移的生物电化学还原，在 1.0×10（-12）至 1.0×10（-11）M 的范围内对过氧化氢的测量得到了线性响应，并且安培检测限为 2.1×10（-13）M。该生物传感器具有出色的操作、储存稳定性和高灵敏度。该生物传感器具有出色的性能，验证了集成组装作为开发新型过氧化氢安培生物传感器的有吸引力的传感元件。
