Kjällman Tanja H M, Peng Hui, Soeller Christian, Travas-Sejdic Jadranka
Polymer Electronic Research Centre, The University of Auckland, Private Bag 92019, Auckland, New Zealand.
Anal Chem. 2008 Dec 15;80(24):9460-6. doi: 10.1021/ac801567d.
Detection of specific sequences of target DNA is of high importance in many fields, especially in medicinal diagnostics. This study focuses on the response of an electrochemical, label-free DNA sensor at two different hybridization temperatures (37 and 44 degrees C). The stem-loop structured probes and the blocking polyethylene glycol molecules were self-assembled on the electrode through S-Au bonding, to form a mixed monolayer employed as the sensing platform. Impedance spectroscopy was used for investigation of the electron transfer processes at a modified gold electrode before and after hybridization with the target DNA. The sensor showed sensitive and selective detection of the target DNA at the lower temperature, whereas the higher temperature affected the dynamics of the hairpin significantly, reflected in an increased sensitivity of the sensor.
在许多领域，尤其是医学诊断中，检测目标DNA的特定序列至关重要。本研究聚焦于一种电化学无标记DNA传感器在两种不同杂交温度（37摄氏度和44摄氏度）下的响应。茎环结构探针和封闭性聚乙二醇分子通过硫金键自组装在电极上，形成用作传感平台的混合单分子层。采用阻抗谱研究修饰金电极在与目标DNA杂交前后的电子转移过程。该传感器在较低温度下对目标DNA表现出灵敏且选择性的检测，而较高温度显著影响发夹结构的动力学，这体现在传感器灵敏度的提高上。
