Download or read book Investigating DNA mediated Charge Transport by Time resolved Spectroscopy written by Eric Daniel Olmon and published by . This book was released on 2012 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: In all organisms, oxidation threatens the integrity of the genome. Numerous studies have suggested that DNA-mediated charge transport (CT) may play an important role in the sequestration, detection, and repair of oxidative damage. To fully understand the mechanism of DNA-mediated CT, it is necessary to characterize transient intermediates that arise during the reaction and to determine the lifetimes of these intermediates. Time-resolved spectroscopy is the most appropriate experimental method for such observations. Each intermediate has a characteristic spectrum. By observing time-dependent changes in the absorption spectrum of the sample, it is therefore possible to determine what species are present at a particular time and how long it exists in solution. Experiments presented here involve the use of time-resolved spectroscopy to better understand the process of DNA-mediated CT.
Download or read book Charge Transfer in DNA written by Hans-Achim Wagenknecht and published by John Wiley & Sons. This book was released on 2006-05-12 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: The past few years have witnessed intense research in this fascinating field as well as many controversial discussions. Now the time is ripe for a comprehensive book covering not only theoretical aspects, but also such mechanistic topics as principles and mechanisms of photoinduced charge injection, transport and trapping in DNA, sequence-dependent DNA dynamics, spectroscopic investigations of hole transport and much more. From the contents: * Principles and Mechanisms of Photoinduced Charge Injection, Transport and Trapping in DNA * Sequence-Dependent DNA Dynamics: The Regulator of DNA-Mediated Charge Transport * Excess Electron Transfer in DNA Probed with Flavin and Thymine Dimer Modified Oligonucleotides * Dynamics of Photoinitiated Hole and Electron Injection in Duplex DNA * Spectroscopic Investigation of Oxidative Hole Transfer via Adenine Hopping in DNA * Chemical Probing of Reductive Electron Transfer in DNA * Chemical Approach for Modulating Hole Transport in DNA * Spectroscopic Investigation of Charge Transfer in DNA * Spectroscopic Probing of Ultrafast Structural Relaxation and Electron Transfer Dynamics in DNA Edited by Hans-Achim Wagenknecht, and written by renowned international authors, this book provides an excellent overview with high quality contributions, making it a "must-have" for everyone working in the field.
Download or read book Femtosecond UV and Infrared Time resolved Spectroscopy of DNA written by Kimberly Desneiges De La Harpe and published by . This book was released on 2011 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: DNA contains the genetic code for all life. The nucleic acid bases that comprise DNA readily absorb ultraviolet light, making them susceptible to photodamage that can lead to mutations and skin cancer. Knowledge of the pathways by which excess electronic energy is dissipated in DNA is important for understanding how photodamage to DNA occurs. The aim of this work is to understand the effect of sequence and secondary structure on the excited-state dynamics in a diverse set of DNA systems. The excited-state dynamics of various GC-containing oligonucleotides were studied by femtosecond transient absorption spectroscopy. Long-lived states with lifetimes at least an order of magnitude slower than the constituent monomers were observed in all the systems studied. Significantly altering the structural conformation of d(GC)9 d(GC)9 through the use of high ionic conditions and low pH revealed that long-lived excited state lifetimes were nearly independent of base stacking geometries and base pairing motifs. The electronic coupling for charge recombination in the long-lived exciplex states of d(GC)9 d(GC)9 is proposed to be large and not significantly altered by helix conformation. The driving force, rather than electronic coupling, for charge recombination is proposed to influence strongly the decay of the long-lived exciplex states in this duplex. Transient absorption experiments were carried out on a genomic DNA sequence to study the effect of sequence disorder on excite-state dynamics. Long-lived excited states were observed in the individual single strands as well as in the duplex of the ras61 oligodeoxynucleotide. The lifetimes of the individual strands were sensitive to composition, with a slower decay observed for the purine-rich strand compared to the pyrimidine-rich strand. In addition, a large ultrafast decay component was observed in the duplex suggesting monomer-like decay pathways are accessible in well-stacked DNA systems. This study shows that long-lived excited states are not an artifact of well-ordered model systems, but are also present in genomic DNA. Isotopic studies revealed a pronounced deuterium isotope effect on the excited-state dynamics of alternating GC-containing oligonucleotides that is not present in non-alternating GC-duplexes. This result parallels those of similar AT-DNAs and is proposed to involve interstrand proton transfer initiated by the formation of an exciplex state with significant charge transfer character. To investigate further the possibility of interstrand proton transfer in DNA duplexes, a series of A- and T-containing oligonucleotides were studied by UV-pump / mid-IR probe spectroscopy. Unique, strong positive bands are observed in alternating AT-DNA, but not in the single- and double-strand non-alternating AT-oligomers. These bands are proposed to be marker bands for proton transfer. Possible absorption bands for excimer states were also observed in (dA)1 in the spectral region of 1500 - 1800 cm−1, supporting previous measurements on polyA.
Download or read book Long Range Charge Transfer in DNA I written by Gary B. Schuster and published by Springer Science & Business Media. This book was released on 2004-03-24 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Charge Transport in DNA Insights from Simulations written by Wolter, Mario and published by KIT Scientific Publishing. This book was released on 2014-10-16 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Charge transport and charge transfer (CT) capabilities of deoxyribonucleic acid (DNA) are investigated. A QM/MM multi-scale framework is applied to calculate the CT capabilities of DNA under conditions resembling the experimental setup. The simulations are able to explain and predict the outcome of experiments and therefore make suggestions in advance. Based on the findings, suitable DNA sequences can be opted for the design of DNA-based devices as nano-scale electronic elements.
Download or read book DNA mediated Charge Transport for Long range Sensing and Protein Detection written by Natalie Bloom Muren and published by . This book was released on 2013 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Functional Organic Materials written by Thomas J. J. Müller and published by John Wiley & Sons. This book was released on 2007-02-12 with total page 622 pages. Available in PDF, EPUB and Kindle. Book excerpt: This timely overview of the syntheses for functional pi-systems focuses on target molecules that have shown interesting properties as materials or models in physics, biology and chemistry. The unique concept allows readers to select the right synthetic strategy for success, making it invaluable for a number of industrial applications. A "must have" for everyone working in this new and rapidly expanding field.
Download or read book Fundamental Aspects of DNA mediated Charge Transport written by Tashica Tréshun Williams and published by . This book was released on 2004 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spectroscopic Characterization of DNA mediated Charge Transfer written by Christopher Ryan Treadway and published by . This book was released on 2003 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book DNA mediated Charge Transport Devices for Protein Detection written by Ariel L. Furst and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ultrafast Dynamics of Metalloporphyrins DNA and Iron Lanthanide Clusters in the Liquid Phase written by Yu Liang and published by KIT Scientific Publishing. This book was released on 2014-05-14 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultraschnelle Dynamik von verschiedenen organischen und anorganischen molekularen Systemen wurde unter Verwendung der zeitaufgelöste Anregungs-Abfrage-Technik in Kombination mit anderen spektroskopischen Methoden untersucht. Diese Dynamik umfasst, z.B. die Relaxationsprozesse in Metalloporphyrins, die Ladungstransfer zwischen Donor und Akzeptor durch DANN-Doppelhelix sowie die Dynamik von Ladungsträger in anorganischen nanostrukturierten zyklischen koordinierten Eisen-Lanthanoide Clustern.
Download or read book DNA mediated Charge Transport Devices for Protein Detection written by Ariel L. Furst and published by . This book was released on 2015 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamics of Photoinduced Charge Transfer Processes in Modified DNA and an Engineered Protein written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The mechanism and the distance dependence of the photoinduced oxidation of guanine in DNA duplexes containing a covalently attached, selectively intercalated acridine derivative as a hole injecting chromophore have been investigated by means of femtosecond time-resolved absorption spectroscopy. The observed steep distance dependence is caused not solely by a decrease in electronic coupling, but also by a concomitant increase in reorganization energy with increasing distance. Additional experiments were performed on the complex between an engineered ligand-binding protein and fluorescein. The results underline the value of time-resolved spectroscopy for the elucidation of excited-state quenching mechanisms in complex biological systems.
Download or read book Organophosphorus Chemistry written by David W. Allen and published by Royal Society of Chemistry. This book was released on 2008-02-04 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: A concise but comprehensive annual survey of a vast field of study enabling the reader to rapidly keep abreast of the latest developments in this specialist area.
Download or read book Femto to Nanosecond Time Resolved Pump Probe Spectroscopy on Electron Transfer in Ferrocenophanone Oxazine 1 Merocyanine 3 TiO2 and Acridine Modified DNA written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Special Issues of the ultrafast electron transfer dynamics in the following donor/acceptor-systems were investigated: (1) Ferrocenophanone/Oxazine-1 in methylene-chloride. It was shown that the time constants of the fs-time-resolved IR-absorption spectra were identical to the UV/VIS spectra. An alternative method to monitor the charge transfer processes was established which is suitable for the investigation of donor/acceptor-systems containing small molecules whose absorption in the UV is superimposed by other optical transitions. (2) Merocyanine-3/TiO2 in aqueous solution. The strongly dispersive recombination dyanmics in the ns-ms time window was studied and theoretical models for explanation were discussed. (3) Short acridine-modified DNA-double-strands in aqueous solution. The activation energy of the time-resolved oxidation-dyanmics of guanine was determined for the first time by temperature dependent measurements as a function of duplex sequence.
Download or read book Charge Transport in DNA Insights From Simulations written by Mario Wolter and published by . This book was released on 2020-10-09 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: Charge transport and charge transfer (CT) capabilities of deoxyribonucleic acid (DNA) are investigated. A QM/MM multi-scale framework is applied to calculate the CT capabilities of DNA under conditions resembling the experimental setup. The simulations are able to explain and predict the outcome of experiments and therefore make suggestions in advance. Based on the findings, suitable DNA sequences can be opted for the design of DNA-based devices as nano-scale electronic elements. This work was published by Saint Philip Street Press pursuant to a Creative Commons license permitting commercial use. All rights not granted by the work's license are retained by the author or authors.
Download or read book DNA mediated Charge Transport in a Biological Context written by Pamela Alisa Sontz and published by . This book was released on 2012 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt:
