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Electrochemistry of Reclox-Modified DNA Monolayer

Reclox 修饰的 DNA 单层的电化学

基本信息

批准号：
18550156
负责人：
YAMANA Kazushige
金额：
$ 2.68万
依托单位：
University of Hyogo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

项目摘要

Redox-resposive DNA assembled monolayer at a metal surface is important in relation to developments of electrochemical DNA sensors and DNA-based electronic devices.We previously prepared 2-O-(2-anthraquinoylmethyl)uridine-containing DNA fragments and found that they can bind selectively and strongly to their complementary DNA sequences. Importantly, the anthraquinone (AQ) moiety can be placed at the predetermined base-pair pocket in double helical DNA. We anticipated that the AQ-modified DNA could be used as an electrochemical probe for DNA sequence determination. The main purpose of the present research is to investigate electrochemical properties of the AQ-modified DNA assembled on a gold electrode surface.First, we prepared AQ-modified DNA duplex attached via thiol-modification onto a gold electrode. One assembled DNA monolayer (system 1) has a single base mismatch between the redox-center and the electrode surface. And the other (system II) consists of the same mismatch but at the … More outside of the redox-center. Electrochemical measurements revealed. that the electron transfer (ET) rate for the fully matched DNA of system I was estimated to be ~50s^<-1>. The mismatch-containing DNA of system I indeed showed much slower ET rate. As expected, in system II, the ET rates for fully matched and mismatched DNA were similar (-50s^<-1>).Then, the presence of mismatch in DNA was determined from the reduced electrochemical responses by a conventional measurement. The technique can be applied to hybridization assays of SNP typing. The important features are that the assay does not require any extra reagents, catalyst, target labeling, and washing steps. Therefore, the present method is a promising way for simple and convenient detection of single base mismatches in DNA.We further investigated other possibility for SNP typing that is based on DNA strand exchange at a metal surface. Redox-modified double strand DNA was assembled as monolayer at a metal surface. We have obtained several experimental results that this type of redox-DNA bound electrodes may be used for SNP detection by a simple electrochemical assays. DNA strand exchange has been applied to developments of aptamer-based biosensors. The results on strand exchange approach will be reported in detail in the next grant period. Less

金属表面氧化还原响应型DNA单层组装对于电化学DNA传感器和DNA电子器件的发展具有重要意义。我们以前制备了含有2-O-(2-蒽喹甲基)尿苷的DNA片段，发现它们可以选择性地与互补的DNA序列结合。重要的是，蒽醌(AQ)部分可以被放置在双螺旋DNA中预定的碱基对口袋中。我们预计，AQ修饰的DNA可以作为DNA序列测定的电化学探针。本研究的主要目的是研究组装在金电极表面的AQ修饰DNA的电化学性质。首先，我们通过硫醇修饰将AQ修饰的DNA双链连接到金电极上。一个组装的DNA单层(系统1)在氧化还原中心和电极表面之间具有单个碱基不匹配。而另一个(系统II)由相同的错配组成，但在…更多的是在氧化还原中心之外。电化学测量显示。系统I的完全匹配的DNA的电子转移(ET)速率估计为~50s^~(-1)~(-1)。含有错配的DNA系统I确实表现出更慢的ET率。正如预期的那样，在系统II中，完全匹配和错配的DNA的ET率相似(-50s^&lt；-1&gt；)。然后，通过常规测量从降低的电化学响应来确定DNA中是否存在错配。该技术可用于SNP分型的杂交分析。重要的特点是，该分析不需要任何额外的试剂、催化剂、靶标记物和洗涤步骤。因此，本方法是一种简便易行的检测DNA单碱基错配的方法。我们进一步探索了基于金属表面DNA链交换的SNP分型的其他可能性。氧化还原修饰的双链DNA以单分子膜的形式组装在金属表面。我们已经获得了一些实验结果，这种类型的氧化还原-DNA结合电极可以用一种简单的电化学方法来检测SNP。DNA链交换已应用于基于适体的生物传感器的开发。关于链交换方法的结果将在下一个赠款期间详细报告。较少