Surface Electrochemistry of DNA Conformational Switches

提出的研究的主要目标是获得功能性脱氧核糖核酸（DNA）的表面电化学的全面知识。DNA作为遗传信息的载体，在生物学中起着举足轻重的作用，了解它的本质是至关重要的。除了典型的单链和双螺旋外，复杂的DNA纳米结构（所谓的DNA构象开关）也可以被构建成具有所需的功能或反应性。通过标准的生化分析，我们发现溶液中完美的双螺旋结构和适当设计的DNA开关可以有效地介导电荷流动。然而，当它们绑定到电极表面时，这不是共识机制；在这种情况下，dna介导和直接电子转移都得到实验观察的支持。

The main goal of the proposed research is to obtain a thorough knowledge of the surface electrochemistry of functional deoxyribonucleic acids (DNA). It is essential to understand the nature of DNA which plays a pivotal role in biology as the carrier of genetic information. Besides typical single strands and double helices, complex DNA nanostructures (so-called DNA conformational switches) can be constructed to have desired functions or reactivities. Using standard biochemical assays, perfect double helices and properly designed DNA switches in solution have been found to efficiently mediate charge flow. However, this is not the consensus mechanism when they are bound to an electrode surface; in that case both DNA-mediated and direct electron transfer are supported by experimental observations. The proposed research will help us to understand structure-conduction correlations in DNA and DNA nanostructures. It also has direct impact on applications: elucidation of the exact charge transport pathway in surface-bound DNA switches is crucial for the development of sensitive electronic biosensors (e.g., for monitoring disease biomarkers in blood). We will initially focus on design and labeling strategies for electrode-bound DNA switches. Combined structural and electrochemical studies will be carried out to discriminate between alternative conduction pathways in these DNA nanostructures and to quantitatively evaluate the electron transfer kinetics. The next phase of this research will comprise a comprehensive study of the signal-switching (charge conduction) mechanism and its structural basis, including real-time spectroscopic and microscopic measurements as well as solid-state experiments.