Development of DNA Detection Method using Photo-induced Electron Transfer

点击翻译按钮获取中文摘要

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.