基于二茂铁标记的电化学DNA生物传感器研究

Research on electrochemical DNA biosensors based on ferrocene labelling

将二茂铁和巯基修饰的脱氧核糖核酸(DNA)探针通过自组装的方式固定到金电极表面,以二茂铁作为电子介体构建电化学DNA传感器,利用杂化前后DNA传感器所展现出峰电流的差异,实现对目标DNA的定量检测。通过研究DNA杂化前后方波伏安法的扫描频率与二茂铁电子介体传输速率关系,优化扫描频率。结果表明:当扫描频率200 Hz时,目标DNA浓度在5. 0×10^(-9)～1. 0×10^(-7)mol/L范围内,峰电流的变化与目标DNA浓度呈线性关系,线性拟合方程式为ΔI_P/I_0(%)=0. 760 95+0. 610 65 c,检测限为1. 7×10^(-9)mol/L(S/N=3)。

The DNA probe modified with ferrocene and sulfydryl immobilized on the surface of gold electrode through self-assembly method,and ferrocene as electronic medium for construction of electrochemical DNA sensor.The target DNA can be quantitatively detected based on the difference of peak current of DNA sensor before and after hybridization.In addition,by studying on relationship between scanning frequency of square wave voltammetric(SWV)and transmission rate of ferrocene electronic medium before and after hybridization with target DNA,optimize scanning frequency.The result shows that while the scanning frequency is 200 Hz,concentration of the target DNA in the range of 5.0×10-9~1.0×10-7 mol/L,peak current change and target DNA concentration have a linear relation linear fitting equationΔIP/I0(%)=0.76095+0.61065 C,and the detection limit is 1.7×10-9 mol/L(S/N=3).