灿烂甲酚蓝在DNA修饰金电极上的电化学行为

利用自组装技术将巯基乙醇固定在金电极表面形成巯基乙醇自组装膜修饰金电极, 用乙基-(3-二甲基氨丙基)碳二亚胺盐酸盐(EDC)和N-羟基琥珀酰亚胺(NHS)为偶联试剂, 分别将鲱鱼精单链DNA(ssDNA)和双链DNA(dsDNA)固定于金电极表面形成ssDNA和dsDNA 修饰电极. 考察了灿烂甲酚蓝(BCB)在不同DNA 修饰电极上的电化学行为,结果表明, BCB 在ssDNA 和dsDNA 修饰电极上的吸附常数分别为1.67×10^4和3.22×10^4 L·mol-1, BCB 与ssDNA 主要以静电作用结合, 而与dsDNA作用存在静电和嵌插两种模式. dsDNA 对BCB 具有更高的亲和力, 使BCB 可以作为一种有效的电化学杂交指示剂.

Electrochemical Behaviors of Brilliant Cresyl Blue on DNA Modified Gold Electrode

DNA modified electrode was prepared by covalent immobilization of ssDNA or dsDNA on a mercaptoethanol monolayer self-assembled gold electrode with the help of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimidehydrochloride (EDC) and N-hydroxysuccinimide (NHS). The electrochemical behaviors of brilliant cresyl blue (BCB) on ssDNA or dsDNA electrodes were studied. BCB had different binding models with ssDNA or dsDNA and the adsorptive constants were 1.67×10^4 L·mol-1 for ssDNA/Au electrode and 3.22×10^4 L·mol-1 for dsDNA/Au electrode. BCB bound to ssDNA via electrostatic interaction while bound to dsDNA through both the electrostatic and intercalative models. The results showed that dsDNA had a stronger appetency for BCB, which indicated that BCB was a suitable electroactive indicator.