Efficient charge transport in DNA diblock oligomers.
The realization of highly efficient photoinduced charge separation across the pi-stacked base pairs in duplex DNA remains elusive. The low efficiencies (<5%) typically observed for charge separation over a dozen or more base pairs are a consequence of slow charge transport and rapid charge recombination. We report here a significant (5-fold or greater) enhancement in the efficiency of charge separation in diblock purine oligomers consisting of two or three adenines followed by several guanines, when compared to oligomers consisting of a single purine or alternating base sequences. This approach to wire-like behavior is attributed to both slower charge recombination and faster charge transport once the charge reaches the G-block in these diblock systems.
Vura-Weis
Josh
J
Department of Chemistry and Argonne-Northwestern Solar Energy Research Center, Northwestern University, Evanston, Illinois 60208, USA.
Wasielewski
Michael R
MR
Thazhathveetil
Arun K
AK
Lewis
Frederick D
FD
D000042:Absorption; D020029:Base Pairing; D001483:Base Sequence; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry* / Q000235:genetics; D004579:Electron Transport; D055029:Inverted Repeat Sequences; D007700:Kinetics; D010640:Phenothiazines / Q000737:chemistry; D055668:Photochemical Processes; D011685:Purine Nucleotides / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet
D010640:Phenothiazines; D011685:Purine Nucleotides; D004247:DNA; C031637:phenothiazine