Xia Peipei, Liu Haiqing, Tian Yang
Department of Chemistry, Tongji University, Siping Road 1239, Shanghai 200092, PR China.
Biosens Bioelectron. 2009 Apr 15;24(8):2470-4. doi: 10.1016/j.bios.2008.12.029. Epub 2008 Dec 25.
Direct and reversible electron transfer of myoglobin (Mb), for the first time, is achieved at nanopyramidal gold surface, which was fabricated by one-step electrodeposition, with redox formal potential of 0.21+/-0.01 V (vs. Ag/AgCl) and an apparent heterogeneous electron-transfer rate constant (k(s)) of 1.6+/-0.2 s(-1). Electrochemical investigation indicates that Mb is stably confined on the nanopyramidal gold surface and maintains electrocatalytic activity toward hydrogen peroxide (H(2)O(2)). The facilitated electron transfer combined with the intrinsic catalytical activity of Mb substantially construct the third-generation biosensor for H(2)O(2). The positive redox potential of Mb at the nanostructured gold electrode gives a strong basis for determination of H(2)O(2) with high selectivity. Besides this advantage, the present biosensor also exhibits quick response time, broad linear range, and good sensitivity. The dynamic detection linear range is from 1 microM to 1.4 mM with a detection limit of 0.5 microM at 3sigma. The striking analytical performance of the present biosensor, as well as the biocompatibility of gold nanostructures provided a potential for continuous, on-line detection of H(2)O(2) in the biological system.
通过一步电沉积制备的纳米金字塔形金表面首次实现了肌红蛋白（Mb）的直接且可逆的电子转移，其氧化还原形式电位为0.21±0.01 V（相对于Ag/AgCl），表观异质电子转移速率常数（k(s)）为1.6±0.2 s(-1)。电化学研究表明，Mb稳定地固定在纳米金字塔形金表面，并保持对过氧化氢（H(2)O(2)）的电催化活性。Mb的促进电子转移与其固有催化活性相结合，实质上构建了用于H(2)O(2)的第三代生物传感器。Mb在纳米结构金电极上的正氧化还原电位为高选择性测定H(2)O(2)提供了有力依据。除了这一优势外，本生物传感器还具有响应时间快、线性范围宽和灵敏度好的特点。动态检测线性范围为1 microM至1.4 mM，在3sigma时检测限为0.5 microM。本生物传感器出色的分析性能以及金纳米结构的生物相容性为生物系统中H(2)O(2)的连续在线检测提供了潜力。
