@article{KumkeDoscheFlehretal.2006, author = {Kumke, Michael Uwe and Dosche, Carsten and Flehr, Roman and Trowitzsch-Kienast, Wolfram and L{\"o}hmannsr{\"o}ben, Hans-Gerd}, title = {Spectroscopic characterization of the artificial siderophore pyridinochelin}, issn = {0939-5075}, year = {2006}, language = {en} } @article{KramerKainmuellerFlehretal.2008, author = {Kramer, Rolf A. and Kainm{\"u}ller, Eva K. and Flehr, Roman and Kumke, Michael Uwe and Bannwarth, Willi}, title = {Quenching of the long-lived Ru(II)bathophenanthroline luminescence for the detection of supramolecular interactions}, year = {2008}, language = {en} } @article{KramerFlehrLayetal.2009, author = {Kramer, Rolf A. and Flehr, Roman and Lay, Myriam and Kumke, Michael Uwe and Bannwarth, Willi}, title = {Comparative studies of different quinoline derivatives as donors in fluorescence-resonance-energy-transfer (FRET) : systems in combination with a (Bathophenanthroline)ruthenium(II) complex as acceptor}, issn = {0018-019X}, doi = {10.1002/hlca.200900235}, year = {2009}, language = {en} } @article{SchwarzeMicklerDoscheetal.2010, author = {Schwarze, Thomas and Mickler, Wulfhard and Dosche, Carsten and Flehr, Roman and Klamroth, Tillmann and L{\"o}hmannsr{\"o}ben, Hans-Gerd and Saalfrank, Peter and Holdt, Hans-J{\"u}rgen}, title = {Systematic investigation of photoinduced electron transfer controlled by internal charge transfer and its consequences for selective PdCl2 coordination}, issn = {0947-6539}, doi = {10.1002/chem.200902281}, year = {2010}, abstract = {Fluoroionophores of fluorophore-spacer-receptor format were prepared for detection of PdCl2 by fluorescence enhancement. The fluorophore probes 1-13 consist of a fluorophore group, in alkyl spacer and a dithiomaleonitrile PdCl2 receptor. First, varying the length of the alkylene spacer (compounds 1-3) revealed, dominant through-space pathway for oxidative photoinduced electron transfer (PET) in CH2-bridged dithiomaleonitrile fluoroionophores. Second. fluorescent probes 4-9 containing two anthracene or pyrene fragments connected through CH2 bridges to the dithiomaleonitrile unit were synthesized. Modulation of the oxidation potential (E-Ox) through electron-withdrawing or -donating groups on the anthracene moiety regulates file thermodynamic driving force for oxidative PET (Delta G(PET)) in bis(anthrylmethylthio)maleonitriles and therefore the fluorescence quantum yields (Phi(f)), too. The new concept was confirmed and transferred to pyrenyl ligands, and fluorescence enhancements (FE) greater than 3.2 in the presence of PdCl2 were achieved by 7 and 8 (FE=5.4 and 5.2). Finally, for comparison, monofluorophore ligands 10-13 were synthesized.}, language = {en} } @article{SchwarzeMicklerDoscheetal.2010, author = {Schwarze, Thomas and Mickler, Wulfhard and Dosche, Carsten and Flehr, Roman and Klamroth, Tillmann and L{\"o}hmannsr{\"o}ben, Hans-Gerd and Saalfrank, Peter and Holdt, Hans-J{\"u}rgen}, title = {Systematic investigation of photoinduced electron transfer controlled by internal charge transfer and its consequences for selective PdCl2 coordination}, issn = {0947-6539}, year = {2010}, abstract = {Fluoroionophores of fluorophore-spacer-receptor format were prepared for detection of PdCl2 by fluorescence enhancement. The fluorescent probes 1-13 consist of a fluorophore group, an alkyl spacer and a dithiomaleonitrile PdCl2 receptor. First, varying the length of the alkylene spacer (compounds 1-3) revealed a dominant through-space pathway for oxidative photoinduced electron transfer (PET) in CH2-bridged dithiomaleonitrile fluoroionophores. Second, fluorescent probes 4-9 containing two anthracene or pyrene fragments connected through CH2 bridges to the dithiomaleonitrile unit were synthesized. Modulation of the oxidation potential (EOx) through electron-withdrawing or -donating groups on the anthracene moiety regulates the thermodynamic driving force for oxidative PET (GPET) in bis(anthrylmethylthio)maleonitriles and therefore the fluorescence quantum yields (f), too. The new concept was confirmed and transferred to pyrenyl ligands, and fluorescence enhancements (FE) greater than 3.2 in the presence of PdCl2 were achieved by 7 and 8 (FE=5.4 and 5.2). Finally, for comparison, monofluorophore ligands 10-13 were synthesized.}, language = {en} } @article{SchwarzeDoscheFlehretal.2010, author = {Schwarze, Thomas and Dosche, Carsten and Flehr, Roman and Klamroth, Tillmann and L{\"o}hmannsr{\"o}ben, Hans-Gerd and Saalfrank, Peter and Cleve, Ernst and Buschmann, Hans-J{\"u}rgen and Holdt, Hans-J{\"u}rgen}, title = {Combination of a CT modulated PET and an intramolecular excimer formation to quantify PdCl2 by large fluorescence enhancement}, issn = {1359-7345}, doi = {10.1039/B919973j}, year = {2010}, abstract = {The [6.6](9,10)anthracenophane 1 (Scheme 1) is a selective fluoroionophore for the detection of PdCl2 with a large fluorescence enhancement factor (I/I-0 > 250).}, language = {en} } @article{SchwarzeDoscheFlehretal.2010, author = {Schwarze, Thomas and Dosche, Carsten and Flehr, Roman and Klamroth, Tillmann and L{\"o}hmannsr{\"o}ben, Hans-Gerd and Saalfrank, Peter and Cleve, Ernst and Buschmann, Hans-J{\"u}rgen and Holdt, Hans-J{\"u}rgen}, title = {Combination of a CT modulated PET and an intramolecular excimer formation to quantify PdCl2 by large fluorescence enhancement}, issn = {1359-7345}, year = {2010}, language = {en} } @article{KienzlerFlehrKrameretal.2011, author = {Kienzler, Andrea and Flehr, Roman and Kramer, Rolf A. and Gehne, Soeren and Kumke, Michael Uwe and Bannwarth, Willi}, title = {Novel Three-Color FRET Tool Box for Advanced Protein and DNA Analysis}, series = {Bioconjugate chemistry}, volume = {22}, journal = {Bioconjugate chemistry}, number = {9}, publisher = {American Chemical Society}, address = {Washington}, issn = {1043-1802}, doi = {10.1021/bc2002659}, pages = {1852 -- 1863}, year = {2011}, abstract = {We report on a new three-color FRET system which we were able to verify in peptides as well as in synthetic DNA. All three chromophores could be introduced by a building block approach avoiding postsynthetic labeling. Additional features are robustness, matching spectroscopic properties, high-energy transfer, and sensitivity. The system was investigated in detail on a set of peptides as well as an array of tailored oligonucleotides. The detailed analysis of the experimental data and comparison with theoretical considerations were in excellent agreement. It is shown that in the case of polypeptides specific interaction with the fluorescence probes has to be considered. In contrast with DNA, the fluorescence probes did not show any indications of such interactions. The novel three-color FRET toolbox revealed the potential for applications studying fundamental processes of three interacting molecules in life science applications.}, language = {en} } @phdthesis{Flehr2012, author = {Flehr, Roman}, title = {Design and development of novel three color-FRET systems in synthetic peptides and oligonucleotides}, address = {Potsdam}, pages = {VII, 149 S.}, year = {2012}, language = {en} } @article{KienzlerFlehrGehneetal.2012, author = {Kienzler, Andrea Altevogt Nee and Flehr, Roman and Gehne, S{\"o}ren and Kumke, Michael Uwe and Bannwarth, Willi}, title = {Verification and biophysical characterization of a New Three-Color Forster Resonance-Energy-Transfer (FRET) System in DNA}, series = {Helvetica chimica acta}, volume = {95}, journal = {Helvetica chimica acta}, number = {4}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0018-019X}, doi = {10.1002/hlca.201100460}, pages = {543 -- 555}, year = {2012}, abstract = {We report on a new three-color FRET system consisting of three fluorescent dyes, i.e., of a carbostyril (=quinolin-2(1H)-one)-derived donor D, a (bathophenanthroline)ruthenium complex as a relay chromophore A1, and a Cy dye as A2 (FRET=Forster resonance-energy-transfer) (cf. Fig. 1). With their widely matching spectroscopic properties (cf. Fig. 2), the combination of these dyes yielded excellent FRET efficiencies. Furthermore, fluorescence lifetime measurements revealed that the long fluorescence lifetime of the Ru complex was transferred to the Cy dye offering the possibility to measure the whole system in a time-resolved mode. The FRET system was established on double-stranded DNA (cf. Fig. 3) but it should also be generally applicable to other biomolecules.}, language = {en} }