细胞色素c在DNA修饰玻碳电极上的直接电化学行为及其在细胞色素c生物传感器中的应用。

Direct electrochemical behavior of cytochrome c on DNA-modified glassy carbon electrode and its application to cytochrome c biosensor.

作者信息

Liu Yun-Chun, Cui Shi-Qiang, Yang Zhou-Sheng

机构信息

School of Chemistry and Materials Science, Anhui Key Laboratory of Functional Molecular Solids, Anhui Normal University, Wuhu, PR China.

出版信息

Anal Sci. 2006 Aug;22(8):1071-4. doi: 10.2116/analsci.22.1071.

DOI:10.2116/analsci.22.1071

PMID:16896244

Abstract

DNA was immobilized on glassy carbon electrodes to fabricate DNA-modified electrodes. The direct electron transfer of horse heart cytochrome c on DNA-modified glassy carbon electrode was achieved. A pair of well-defined redox peaks of cytochrome c appeared at Epc = -0.017 V and Epa = 0.009 V (vs. Ag/AgCl) in 10 mM phosphate buffer solution (pH 7.0) at a scan rate of 50 mV/s. The electron transfer coefficient (alpha) and the standard rate constant of the surface reaction (Ks) of cytochrome c on DNA-modified electrodes could be estimated to be 0.87 and 34.52 s(-1), respectively. The DNA-modified glassy carbon electrode could be applied to detect cytochrome c by means of differential pulse voltammetry (DPV). The cathodic peak current was proportional to the quantity of cytochrome c in the range of 4.0 x 10(-6) M to 1.2 x 10(-5) M. The correlation coefficient is 0.996, and with the detection limit was 1.0 x 10(-6) M (three times the ratio of signal to noise, S/N = 3).

摘要

将DNA固定在玻碳电极上以制备DNA修饰电极。实现了马心细胞色素c在DNA修饰玻碳电极上的直接电子转移。在10 mM磷酸盐缓冲溶液（pH 7.0）中，扫描速率为50 mV/s时，细胞色素c出现一对清晰的氧化还原峰，Epc = -0.017 V，Epa = 0.009 V（相对于Ag/AgCl）。细胞色素c在DNA修饰电极上的电子转移系数（α）和表面反应的标准速率常数（Ks）分别估计为0.87和34.52 s(-1)。DNA修饰玻碳电极可通过差分脉冲伏安法（DPV）用于检测细胞色素c。阴极峰电流与细胞色素c的量在4.0×10(-6) M至1.2×10(-5) M范围内成正比。相关系数为0.996，检测限为1.0×10(-6) M（信噪比S/N = 3的三倍）。