Yin Fan, Shin Hoon-Kyu, Kwon Young-Soo
Department of Electrical Engineering, Dong-A University, Busan 604-714, South Korea; Department of Chemistry, Changshu Institute of Technology, Changshu 215500, PR China.
Talanta. 2005 Jul 15;67(1):221-6. doi: 10.1016/j.talanta.2005.02.021. Epub 2005 Mar 23.
The present paper describes the modification of hemoglobin (Hb)-octadecylamine (ODA) Langmuir-Blodgett (LB) film on a gold electrode surface to develop a novel electrochemical biosensor for the detection of hydrogen peroxide. Atomic force microscopy (AFM) image of Hb-ODA LB film indicated Hb molecules existed in ODA layer in a well-ordered and compact form. The immobilized Hb displayed a couple of stable and well-defined redox peaks with an electron transfer rate constant of 4.58+/-0.95s(-1) and a formal potential of -185mV (versus Ag/AgCl) in phosphate buffer (1.0mM, pH 5.0) contain 0.1M KCl at a scan rate of 200mVs(-1), characteristic of Hb heme Fe(III)/Fe(II) redox couple. The formal potential of Hb heme Fe(III)/Fe(II) redox couple in ODA film shifted linearly between pH 5 and 8 with a slope of -23.8mVpH(-1), suggesting that proton took part in electrochemical reaction. The ODA could accelerate the electron transfer between Hb and the electrode. This modified electrode showed an electrochemical activity to the reduction of hydrogen peroxide (H(2)O(2)) without the aid of any electron mediator.
本文描述了在金电极表面对血红蛋白（Hb）-十八烷基胺（ODA）朗缪尔-布洛杰特（LB）膜进行修饰，以开发一种用于检测过氧化氢的新型电化学生物传感器。Hb-ODA LB膜的原子力显微镜（AFM）图像表明，Hb分子以有序且紧密的形式存在于ODA层中。固定化的Hb在含0.1M KCl的磷酸盐缓冲液（1.0mM，pH 5.0）中，扫描速率为200mVs(-1)时，显示出一对稳定且明确的氧化还原峰，电子转移速率常数为4.58±0.95s(-1)，形式电位为-185mV（相对于Ag/AgCl），这是Hb血红素Fe(III)/Fe(II)氧化还原对的特征。在ODA膜中，Hb血红素Fe(III)/Fe(II)氧化还原对的形式电位在pH 5至8之间呈线性变化，斜率为-23.8mVpH(-1)，表明质子参与了电化学反应。ODA可以加速Hb与电极之间的电子转移。该修饰电极在不借助任何电子媒介体的情况下，对过氧化氢（H(2)O(2)）的还原显示出电化学活性。
