title: Photocurrent generation through charge-transfer processes in noncovalent perylenediimide/DNA complexes.
abstract: The charge-transfer process in noncovalent perylenediimide (PDI)/DNA complexes has been investigated by using nanosecond laser flash photolysis (LFP) and photocurrent measurements. The PDI/DNA complexes were prepared by inclusion of cationic PDI molecules into the artificial cavities created inside DNA. The LFP experiments showed that placement of the PDI chromophore at a specific site and included within the base stack of DNA led to the efficient generation of a charge-separated state with a long lifetime by photoexcitation. When two PDI chromophores were separately placed at different positions in DNA, the yield of the charge-separated state with a long lifetime was dependent upon the number of A-T base pairs between the PDIs, which was explained by electron hopping from one PDI to another. Photocurrent generation of the DNA-modified electrodes with the complex was also dependent upon the arrangement of the PDI chromophores. A good correlation was obtained between observed charge separation and photocurrent generation on the PDI/DNA-modified electrodes, which demonstrated the importance of the defined arrangement and assembly of organic chromophores in DNA for efficient charge separation and transfer in multichromophore arrays.
authors.affiliation: Department of Materials Science and Chemistry, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280 (Japan). takada@eng.u-hyogo.ac.jp.
authors.forename: Tadao
authors.initials: T
authors.lastname: Takada
authors.forename: Misa
authors.initials: M
authors.lastname: Ido
authors.forename: Akane
authors.initials: A
authors.lastname: Ashida
authors.forename: Mitsunobu
authors.initials: M
authors.lastname: Nakamura
authors.forename: Mamoru
authors.initials: M
authors.lastname: Fujitsuka
authors.forename: Kiyohiko
authors.initials: K
authors.lastname: Kawai
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Majima
authors.forename: Kazushige
authors.initials: K
authors.lastname: Yamana
mesh_terms: D020029:Base Pairing; D001483:Base Sequence; D001665:Binding Sites; D004396:Coloring Agents / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D055664:Electrochemical Techniques; D004566:Electrodes; D004579:Electron Transport; D007094:Imides / Q000737:chemistry*; D008969:Molecular Sequence Data; D010569:Perylene / Q000031:analogs & derivatives* / Q000737:chemistry; D055668:Photochemical Processes
chemical_list: D004396:Coloring Agents; D007094:Imides; C521332:perylenediimide; D010569:Perylene; D004247:DNA
keywords: DNA; charge transfer; chromophores; perylenediimides; photochemistry