基于金纳米粒子的QCM实时检测DNA错配的研究

In-situ measurements of DNA mismatch basing on gold nanoparticle by quartz crystal microbalance(QCM)

利用石英晶体微天平(QCM)技术,用双硫醇分子作为连接剂,将金纳米粒子固定于金电极表面,以人类p53基因片断为DNA探针,研究了其在QCM金电极表面的固定、杂交和错配,重点探讨了金纳米粒子修饰的DNA错配碱基个数和错配位点对杂交的影响。在实验条件下,金纳米粒子在QCM金电极表面的修饰使其灵敏度得到了明显提高;而且,错配碱基个数和错配碱基位点的差异都对杂交产生了不同程度的影响。

The modification of the human p53 gene segment as the probe onto the gold electrode surface and the hybridization of probe DNA with the complementary strand and the noncomplementary strand, especially the influence of the mismatch number and the site, were studied using quartz crystal microbalance （QCM）. And the gold nanoparticles were linked onto the surface of the QCM with the 1,6 -hexanedithiol modified gold electrode. The results show that the sensitivity of QCM was improved obviously due to the using of the gold nanopartide. Moreover, the difference of the mismatch number and the site had great influence on the hybridization. The hybridization efficiency was reduced 21% when one base mismatched. And the hybridization efficiency reduced to 20% when the near mismatch number up to three. Further more, hybridization did not occur when the mismatch site was interphase but the mismatch number was changeless. The same results were proved by the experiment of the fluorescence spectrum.