title: Efficient Charge Transport via DNA G-Quadruplexes.
abstract: The dynamics and efficiency of photoinduced charge transport has been investigated in DNA capped hairpins possessing a stilbenedicarboxamide (Sa) hole donor and stilbenediether (Sd) hole acceptor separated by DNA G-quadruplex structures possessing 2-to-4 tetrads by means of femtosecond and nanosecond transient absorption spectroscopy with global analysis. The results for the quadruplex structures are compared with those for the corresponding duplex structures having G-C base pairs in place of the G-tetrads. Following photoinduced charge separation to form a contact radical ion pair, hole transport to form the Sa-•/Sd+•charge-separated state is slower but more efficient for the quadruplex vs duplex structures. Thus, the G-quadruplex serves as an effective conduit for positive charge rather than as a hole trap when inserted into a duplex, as previously postulated.
authors.affiliation: Department of Chemistry and Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University , Evanston, Illinois 60208-3113, United States.
authors.forename: Arun K
authors.initials: AK
authors.lastname: Thazhathveetil
authors.affiliation: Department of Chemistry and Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University , Evanston, Illinois 60208-3113, United States.
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Harris
authors.affiliation: Department of Chemistry and Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University , Evanston, Illinois 60208-3113, United States.
authors.forename: Ryan M
authors.identifier: 0000-0002-5108-0261
authors.initials: RM
authors.lastname: Young
authors.affiliation: Department of Chemistry and Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University , Evanston, Illinois 60208-3113, United States.
authors.forename: Michael R
authors.identifier: 0000-0003-2920-5440
authors.initials: MR
authors.lastname: Wasielewski
authors.affiliation: Department of Chemistry and Argonne-Northwestern Solar Energy Research (ANSER) Center, Northwestern University , Evanston, Illinois 60208-3113, United States.
authors.forename: Frederick D
authors.identifier: 0000-0002-3669-2796
authors.initials: FD
authors.lastname: Lewis
mesh_terms: D004247:DNA / Q000737:chemistry*; D004987:Ethers / Q000737:chemistry; D054856:G-Quadruplexes; D015394:Molecular Structure; D055668:Photochemical Processes; D013267:Stilbenes / Q000737:chemistry; D013816:Thermodynamics
chemical_list: D004987:Ethers; D013267:Stilbenes; D004247:DNA