利用自组装单分子层技术在传感器金膜表面构建DNA探针修饰电极的研究

Construction of Electrode Modified with DNA Probe at the Surface of Sensor Gold Membrane by Self-assembled Monolayer Technique

目的 在压电基因传感器阵列表面构建 DNA探针修饰的金膜电极。方法 利用自组装单分子层 (self-assembled m onolayer,SAM)技术将 5′端带有巯基的 DNA探针共价交联到压电基因传感器的金膜表面 ,利用循环伏安计 (circled voltam meter,CV) ,扫描隧道显微镜 (scanning tunnel m icroscope,STM)分别观察探针交联前后金膜表面电化学表征及微观结构的改变。结果 CV测量结果显示随着 DNA探针在传感器金膜表面的吸附 ,界面电容减小 ;STM扫描结果更是直观地显示探针非常均匀、规整地在金膜电极表面形成一层 SAM。结论 利用 SAM技术可以很好地将 DNA探针固定在压电基因传感器金膜表面。

OBJECTIVETo construct electrode modified with DNA probe at the surface of gold membrane of piezoelectric gene sensors array. METHODSDNA probe with thiol group in 5′ terminus was covalently linked to the gold surface of piezoelectric gene sensors by self-assembled monolayer (SAM) technique. Changes in the electrochemical parameters and microscopic construction in gold membrane were observed with circled voltammeter (CV) and scanning tunnel microscope (STM) respectively. RESULTSMeasured by CV showed that surface electric capacity decreased following the absorption of DNA probe on the surface of gene sensor. And a SAM on the surface of gold membrane formed very even by DNA probe was directly observed by STM scanning. CONCLUSIONSDNA probe was definitely immobilized at the surface of gold membrane of quartz oscillation sensor by SAM.