Development of DNA Detection Method using Photo-induced Electron Transfer

双链脱氧核糖核酸有望显示出基于堆叠核酸碱基的π电子阵列结构，即所谓的π-Way结构的分子导线的功能。研究了多核苷酸中插入或结合到碱基对上的电子供体和受体之间DNA介导的光诱导电子转移。我们已经报道了两亲插层剂C_&lt；18&gt；AO^+可以在空气-水界面插入DNA和其他多核苷酸，并在固体载体上转移具有有序DNA阵列的复合单分子膜。本文报道了DNA介导的光诱导电子转移。在双链DNA、RNA和其他阴离子聚合物的水相亚相上制备了二元混合单分子膜(两亲供体C18AO+和阳离子两亲分子2C18N+2C1)和三元混合膜(两亲性受体C12BphC5V2+)，用朗缪尔薄膜天平荧光显微镜同时测量了气液界面的压强等温线和荧光光谱。C12BphC5V2+分子对C18AO+荧光有明显的电子转移猝灭作用。DNA和RNA增强了荧光猝灭，但合成的阴离子聚合物不影响荧光猝灭。这种现象只在双链DNA和RNA中观察到。因此，单链DNA和RNA与互补的DNA和RNA的杂交可以通过DNA和RNA与三元单层结合的光诱导电子转移来检测。

Double-stranded DNA is expected to show function as a molecular wire based on the π-electron array structure, so-called "π-ways", of stacked nucleic acid bases. DNA-mediated photo-induced electron transfer between electron donors and acceptors which are intercalated or bound to base pairs in polynucleotides has been investigated. We have reported that the amphiphilic intercalator, C_<18>AO^+, monolayer can be intercalated into DNA and other polynucleotides at the air-water interface and the composite monolayer with ordered DNA array can be transferred on the solid support.Here we report, DNA-mediated photo-induced electron transfer in the monolayers containing electron donor and acceptor at the air-water interface. Binary mixed monolayers (an amphiphilic donor, C18AO+ and cationic amphiphile, 2C18N+2C1) and ternary mixture (an amphiphilic acceptor C12BphC5V2+) were prepared on the aqueous subphases of double-stranded DNA, RNA and other anionic polymers.Pressure-area isotherms and fluorescence spectra were measured simultaneously at the air-water interface by Langmuir film balance equipping fluorescence microscope. Electron transfer quenching of C18AO+ fluorescence by C12BphC5V2+ molecule are clearly. Fluorescence quenching was enhanced by DNA and RNA, but not affected by synthetic anionic polymers. This phenomenon is observed only in the double-stranded DNA and RNA. Therefore hybridization of single-stranded DNA and RNA with complementary DNA and RNA can be detected by the photo-induced electron transfer through DNA and RNA combined with the ternary monolayer.