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Charge transport in DNA
Drevený, Lukáš ; Mravec, Filip (referee) ; Vala, Martin (advisor)
In this bachelor thesis were investigated charge transport (CT) through a duplexes of DNA by stationary fluorescence spectroscopy, with a fluorescent analogue of adenine - 2-aminopurine (Ap), as fluorescent probe. The aim of study was an influence of changes in the structure of duplexes DNA:DNA or DNA:RNA and effect of the presence of Hg(II) in double-stranded DNA:DNA containing a mutation thymine-thymine in the chain, in the efficiency of charge transfer along the DNA strand. Firstly, in the experimental part was investigated a efficiency of incorporation of Ap into the DNA strand from an excitation spectra and secondly, from the integrals of the emission spectras the quenched factor was calculated. It was found that the Ap can be better incorporated into the chain of DNA:RNA, which is not as rigid as a string of DNA:DNA and thus may be better accepted by the nearby bases in the chain; furthermore, it was found that the photo-induced charge transfer (PET) through the DNA strand sharply drops after exceeding a temperature corresponding with melting point of DNA chain, at which the string of DNA is unraveling. It was also found that the presence of Hg(II) in the chain of DNA:DNA does not adversely affect a charge transfer, but on the contrary, the string is after integration of Hg(II) into the chain more stable and the melting point is shifted to higher temperatures. In this thesis it was proved that photoinduced charge transfer is very sensitive process and could be used for detection of even tiny changes in the structure of nucleic acids.
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Excited-state proton transfer as a tool for characterization of coloid particles
Richterová, Veronika ; Pilgrová, Tereza (referee) ; Mondek, Jakub (advisor)
This bachelor thesis deals with the study of excited-state proton transfer in micellar systems. At first critical micelle concentration of surfactants CTAB, SDS and Triton X-100 was determined. Further the steady-state and time-resolved fluorescence of probes that undergo excited-state proton transfer with these surfactants was measured. As probes were chosen 1-naphthol, HPTS and 3HNA. Deprotonation rates of 1-napthol and HPTS and average lifetime of 3HNA were calculated from time-resolved measurement. Steady-state fluorescence was used for observation surfactants influence on excited-state proton transfer.
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Excited-state proton transfer as a tool for characterization of coloid particles
Richterová, Veronika ; Pilgrová, Tereza (referee) ; Mondek, Jakub (advisor)
This bachelor thesis deals with the study of excited-state proton transfer in micellar systems. At first critical micelle concentration of surfactants CTAB, SDS and Triton X-100 was determined. Further the steady-state and time-resolved fluorescence of probes that undergo excited-state proton transfer with these surfactants was measured. As probes were chosen 1-naphthol, HPTS and 3HNA. Deprotonation rates of 1-napthol and HPTS and average lifetime of 3HNA were calculated from time-resolved measurement. Steady-state fluorescence was used for observation surfactants influence on excited-state proton transfer.
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Charge transport in DNA
Drevený, Lukáš ; Mravec, Filip (referee) ; Vala, Martin (advisor)
In this bachelor thesis were investigated charge transport (CT) through a duplexes of DNA by stationary fluorescence spectroscopy, with a fluorescent analogue of adenine - 2-aminopurine (Ap), as fluorescent probe. The aim of study was an influence of changes in the structure of duplexes DNA:DNA or DNA:RNA and effect of the presence of Hg(II) in double-stranded DNA:DNA containing a mutation thymine-thymine in the chain, in the efficiency of charge transfer along the DNA strand. Firstly, in the experimental part was investigated a efficiency of incorporation of Ap into the DNA strand from an excitation spectra and secondly, from the integrals of the emission spectras the quenched factor was calculated. It was found that the Ap can be better incorporated into the chain of DNA:RNA, which is not as rigid as a string of DNA:DNA and thus may be better accepted by the nearby bases in the chain; furthermore, it was found that the photo-induced charge transfer (PET) through the DNA strand sharply drops after exceeding a temperature corresponding with melting point of DNA chain, at which the string of DNA is unraveling. It was also found that the presence of Hg(II) in the chain of DNA:DNA does not adversely affect a charge transfer, but on the contrary, the string is after integration of Hg(II) into the chain more stable and the melting point is shifted to higher temperatures. In this thesis it was proved that photoinduced charge transfer is very sensitive process and could be used for detection of even tiny changes in the structure of nucleic acids.
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