摘要
报道了一种基于亲和素修饰磁珠表面的电化学检测特殊序列靶DNA的新策略.其方法如下:首先磁珠表面用亲和素功能化,然后利用生物素-亲和素的特殊识别作用,将生物素-探针DNA固定在磁珠表面,通过分子杂交,将另一条含有二茂铁标记互补碱基序列的靶DNA,进行识别,结合形成双链.利用示差脉冲伏安法检测二茂铁产生的电化学信号进行定量.在最佳条件下,二茂铁的峰电流强度与靶DNA浓度的对数在10-9-10-7M范围内呈线性关系.其线性回归方程:I(μA)=5.598+0.549lgCDNA,相关系数为0.9962,检测限是3.5×10-10M(S/N=3).此外,该传感器具有良好的选择性,它能识别单碱基错配序列的靶DNA.
The paper reported a new strategy for the electrochemical detection of specific sequence DNA based on streptavidin functionalized magnetic beads. First, the biotin-ssDNA as probe and immobilized on the surface of the streptavidin functionalized magnetic beads through the specific binding of the biotin-avidin. The target DNA labeled with ferrocene was recognized by probe DNA and formed the dsDNA through molecule hybridization reaction. Different pulse voltmmetry was employed to measure the electrochemical signal of the ferrocene. The peak current intensities of ferrocene were linear with the logarithm of the target concentration from 10^-9 to 10^-7 M with a detection of limit of 3.5 × 10^- 10 M（S/N = 3）, The linear regression equation was I = 5. 598 ＋ 0. 549 log c, with a correlation coefficient of 0. 9962. Moreover, the biosensor shows good selectivity, even though it can distinguish single base mismatch target DNA sequence.
出处
《安徽师范大学学报（自然科学版）》
CAS
北大核心
2014年第1期16-19,共4页
Journal of Anhui Normal University(Natural Science)
基金
国家自然科学基金(20675002)
关键词
磁珠
二茂铁
DNA
差示脉冲伏安法
magnetic bead ferrocene
DNA
different pulse voltmmetry
