Shi Guoyue, Sun Zhiyu, Liu Meichuan, Zhang Li, Liu Ye, Qu Yunhe, Jin Litong
Department of Chemistry, East China Normal University, 3663 Zhongshan Road(N), Shanghai, 200062, People's Republic of China.
Anal Chem. 2007 May 15;79(10):3581-8. doi: 10.1021/ac062034g. Epub 2007 Apr 17.
In this paper, layer-by-layer {Hb/SiO2}n films assembled by alternate adsorption of positively charged hemoglobin (Hb) and vapor-surface sol-gel deposition of silica at 50 degrees C onto a glassy carbon electrode were reported. The result films were characterized with cyclic voltametery, electrochemical impedance spectroscopy, UV-vis spectroscopy, and SEM, and the direct electrochemical and electrocatalytic properties of Hb in these layer-by-layer films were investigated. A pair of well-defined quasi-reversible cyclic voltammetric peaks were observed, and the formal potential of the heme FeIII/FeII redox couple was found to be -0.330 V(vs SCE). The electron-transfer behavior of Hb in {Hb/SiO2}n films was dependent on the vapor temperature, the number of layers, and the pH of the Hb solution, based on which a set of optimized conditions for film fabrication was inferred. The hemoglobin in{Hb/SiO2}n films displayed good electrocatalytic activity to the reduction of hydrogen peroxide, and H2O2 had linear current response from 1.0 x 10(-6) to 2.0 x 10(-4) M with a detection limit of 5.0 x 10(-7) M (S/N = 3). The apparent heterogeneous electron-transfer rate constant (ks) was 1.02 +/- 0.03 s(-1), and the apparent Michaeli-Menten constant (Kmapp) was 0.155 mM, indicating a potential application in the third-generation biosensor.
本文报道了通过在50℃下将带正电荷的血红蛋白（Hb）交替吸附与二氧化硅的气相表面溶胶 - 凝胶沉积组装在玻碳电极上形成的逐层{Hb/SiO₂}n膜。用循环伏安法、电化学阻抗谱、紫外 - 可见光谱和扫描电子显微镜对所得膜进行了表征，并研究了这些逐层膜中Hb的直接电化学和电催化性能。观察到一对明确的准可逆循环伏安峰，血红素FeIII/FeII氧化还原对的形式电位为-0.330 V（vs SCE）。基于此推断出一组膜制备的优化条件，{Hb/SiO₂}n膜中Hb的电子转移行为取决于气相温度、层数和Hb溶液的pH值。{Hb/SiO₂}n膜中的血红蛋白对过氧化氢的还原表现出良好的电催化活性，H₂O₂在1.0×10⁻⁶至2.0×10⁻⁴ M范围内有线性电流响应，检测限为5.0×10⁻⁷ M（S/N = 3）。表观异相电子转移速率常数（ks）为1.02±0.03 s⁻¹，表观米氏常数（Kmapp）为0.155 mM，表明其在第三代生物传感器中的潜在应用。
