Photocleavage of Nucleic Acids

Armitage, Bruce A.

doi:10.1021/cr960428+

Cited by 717 publications

(554 citation statements)

References 183 publications

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“…[7][8][9] d6 complexes such as those of ruthenium( II) or rhenium(I) have been extensively investigated as an advantage of these compounds is that their photochemical and photophysical properties can be readily tuned. For instance it is often possible to select a complex with an excited state having an appropriate redox potential or one which shows exquisite sensitivity to its environment.…”

Section: Introductionmentioning

confidence: 99%

Excited state behaviour of substituted dipyridophenazine Cr(iii) complexes in the presence of nucleic acids

Wojdyła

Smith

Vasudevan

et al. 2010

Photochem Photobiol Sci

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The photophysics and photochemistry of [Cr(phen) 2 (dppz)] 3+ and its 11,12-substituted derivatives [Cr(phen) 2 (X 2 dppz)] 3+ {X = Me or F} have been studied in the presence of purine nucleotides or DNA using steady state and time-resolved absorption and luminescence spectroscopy. 5′-Adenosine monophosphate (5′-AMP) shows only a weak interaction with the excited states of each complex. By contrast they are efficiently quenched by 5′-guanosine monophosphate (5′-GMP), consistent with photo-induced electron transfer. Laser flash photolysis spectroscopy in the presence of 5′-GMP suggests that both forward and back electron-transfers are rapid. All complexes also display a strong affinity for DNA and evidence for both static and dynamic quenching mechanisms is provided.Graphical Abstract:

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Section: Introductionmentioning

confidence: 99%

Excited state behaviour of substituted dipyridophenazine Cr(iii) complexes in the presence of nucleic acids

Wojdyła

Smith

Vasudevan

et al. 2010

Photochem Photobiol Sci

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“…Mechanistic studies of charge transfer in DNA have attracted considerable attention because of their relevance to the development of DNA molecular wires (3) and the involvement in DNA oxidative lesion and strand cleavage (4,5). There are many mechanistic studies for the ''one-dimensional'' conductivity in the double helix (6)(7)(8).…”

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confidence: 99%

Direct observation of hole transfer through double-helical DNA over 100 Å

Takada

Kawai

Fujitsuka

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

161

177

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Mechanism of photo-induced electron transfer and the subsequent hole transfer in DNA has been studied extensively, but so far we are not aware of any reliable report of the observation of the long-distance hole-transfer process. In this article, we demonstrate the results of direct observation for the long-distance hole transfer in double-helical DNA over 100 Å with time-resolved transient absorption measurements. DNA conjugated with naphthalimide (NI) and phenothiazine (PTZ) (which worked as electron-acceptor and donor molecules, respectively) at both 5 ends was synthesized to observe the hole-transfer process. Site-selective charge injection into G by means of the adenine-hopping process was accomplished by excitation of NI with a 355-nm laser flash. Transient absorption around 400 nm, which was assigned to the NI radical anion, was observed immediately after the irradiation of a laser flash, indicating that the charge separation between NI and the nearest G occurred. Then, the transient absorption of the PTZ radical cation (PTZ •؉ ) at 520 nm was emerged, which was attributed to the hole transfer through DNA to the PTZ site. By monitoring the time profiles of the transient absorption of PTZ •؉ for NI-A6-(GA)n-PTZ and NI-A6-(GT)n-PTZ (n ‫؍‬ 2, 3, 4, 6, 8, 12) (base sequences correspond to those for DNA modified with NI), the long-distance hole-transfer process from G to PTZ, which occurred in the time scale of microsecond to millisecond, was observed directly. By assuming an average distance of 3.4 Å between base-pairs, total distance reaches 100 Å for n ‫؍‬ 12 sequences. Our results clearly show the direct observation of the long-distance hole transfer over 100 Å.D ouble-helical DNA, which has unique structural properties, is a promising candidate for molecular electronic devices and a scaffold for two-and three-dimensional nanostructures (1, 2). Mechanistic studies of charge transfer in DNA have attracted considerable attention because of their relevance to the development of DNA molecular wires (3) and the involvement in DNA oxidative lesion and strand cleavage (4, 5). There are many mechanistic studies for the ''one-dimensional'' conductivity in the double helix (6-8). Factors controlling charge-transfer properties in DNA (such as electronic coupling between donor and acceptor, structural dynamics, reorganization energy, etc.) have been discussed (9-14), and the mechanism for charge transfer, especially hole transfer over long distances in DNA, is the subject of experimental and theoretical studies.Generally, experimental studies of charge transfer in DNA have been performed by time-resolved measurements and electrophoresis analysis (15)(16)(17)(18)(19). A model of a multistep holehopping mechanism, which was proposed by Giese and coworkers (20), is the most widely adopted. An alternative mechanism in which delocalized hole migrates by means of a polaron-like mechanism was proposed by Schuster and coworkers (18). Strand-cleavage studies using PAGE analysis have provided valuable information about the seque...

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“…Due to the biological implications, the studies about the charge migration in DNA were related to physiological processes: the possibility and efficiency of charge transfer is significant, because the migration of the radical cation is a critical issue to understand problems related to radiation damage and mutation [27,28].…”

Section: Electron Transfer Through Dnamentioning

confidence: 99%

Biomolecules and Pure Carbon Aggregates: An Application Towards “Green Electronics”

Srivastava¹

2018

Green Electronics

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Abstract"Green electronics" is a novel scientific term which aims to identify the compounds of natural origin (economically safe and biodegradable) and establish economically efficient route for production of synthetic materials. The purpose of green electronics is to create path for the production of human and environmental friendly electronics and the integration of electronics with living tissue in particular. These researches may help to fulfill not only the organic electronics to deliver low cost energy efficient materials and devices, but also achieve unimaginable functionalities for electronics. In this chapter we have considered the molecular electronic devices biomolecules: deoxyribonucleic acid (DNA) and pure carbon aggregates: (carbon nanotubes (CNTs)/graphene), their properties and applications.

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Photocleavage of Nucleic Acids

Cited by 717 publications

References 183 publications

Excited state behaviour of substituted dipyridophenazine Cr(iii) complexes in the presence of nucleic acids

Excited state behaviour of substituted dipyridophenazine Cr(iii) complexes in the presence of nucleic acids

Direct observation of hole transfer through double-helical DNA over 100 Å

Biomolecules and Pure Carbon Aggregates: An Application Towards “Green Electronics”

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