纳米金修饰电极和探针载体的DNA电化学发光分析方法研究

Electrogenerated chemiluminesence detection for DNA hybridization based on gold nanoparticles as electrode-modified materials and carrying multiple probes

提出以纳米金修饰电极和以纳米金粒子作DNA探针载体的电化学发光检测DNA新方法．首先将纳米金自组装在金电极上，再将含巯基的目标SS-DNA固定于纳米金修饰的电极上，然后与以纳米金粒子作载体的电化学发光DNA探针进行杂交反应，将此电极做工作电极，在含有三丙胺的溶液中进行电化学发光测量．在选定实验条件下，检测囊肿纤维DNA片断（20base）的线性范围为1．0×10^-12～1．0×10^-9mol／L，相关系数为0．9954。检出限为5．0×106-13mol／L．实验结果表明，纳米金具有较大的比表面积，可增强DNA在电极上的固定量，从而增强电化学发光检测信号，提高方法的灵敏度．

A novel sensitive electrogenerated chemiluminescence （ECL） method for the detection DNA hybridization was developed. Gold nanoparticles were used as both electrode-modified materials and a carrier of the ECL probe. It was found that the sensitivity was greatly enhanced at electrode modified by self-assembled gold nanoparticles due to the enlargement of the electrode surface area and the enhancement of the immobilization amount of target DNA on the electrode. The integrated ECL intensity was increased about 3.9-fold when the ECL probe of Ru（bpy）2 （dcbpy） NHS-DNA-Au was used. The results showed that the integrated ECL intensity was linearly related to the concentration of target DNA from 1.0 × 10^-12 mol/L to 1.0 ×10^-9 mol/L with a detection limit of 5.0 × 10 ^- 13 mol/L target ENA.