TY - JOUR A1 - Ast, S. A1 - Fischer, Tobias A1 - Müller, H. A1 - Mickler, W. A1 - Schwichtenberg, M. A1 - Rurack, Knut A1 - Holdt, H.-J. T1 - Integration of the 1,2,3-triazole 'click' motif as a potent signalling element in metal ion responsive fluorescent probes JF - Chemistry - A European journal N2 - In a systematic approach we synthesized a new series of fluorescent probes incorporating donor–acceptor (D-A) substituted 1,2,3-triazoles as conjugative π-linkers between the alkali metal ion receptor N-phenylaza-[18]crown-6 and different fluorophoric groups with different electron-acceptor properties (4-naphthalimide, meso-phenyl-BODIPY and 9-anthracene) and investigated their performance in organic and aqueous environments (physiological conditions). In the charge-transfer (CT) type probes 1, 2 and 7, the fluorescence is almost completely quenched by intramolecular CT (ICT) processes involving charge-separated states. In the presence of Na+ and K+ ICT is interrupted, which resulted in a lighting-up of the fluorescence in acetonitrile. Among the investigated fluoroionophores, compound 7, which contains a 9-anthracenyl moiety as the electron-accepting fluorophore, is the only probe which retains light-up features in water and works as a highly K+/Na+-selective probe under simulated physiological conditions. Virtually decoupled BODIPY-based 6 and photoinduced electron transfer (PET) type probes 3–5, where the 10-substituted anthracen-9-yl fluorophores are connected to the 1,2,3-triazole through a methylene spacer, show strong ion-induced fluorescence enhancement in acetonitrile, but not under physiological conditions. Electrochemical studies and theoretical calculations were used to assess and support the underlying mechanisms for the new ICT and PET 1,2,3-triazole fluoroionophores. KW - Charge transfer KW - Click chemistry KW - Electron transfer KW - Fluorescent probes KW - Metal ions PY - 2013 DO - https://doi.org/10.1002/chem.201201575 SN - 0947-6539 SN - 1521-3765 VL - 19 IS - 9 SP - 2990 EP - 3005 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-27742 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cordsmeier, Leo A1 - Hahn, Marc Benjamin T1 - DNA Stability in Biodosimetry, Pharmacy and DNA Based Data-Storage: Optimal Storage and Handling Conditions JF - ChemBioChem N2 - DNA long-term stability and integrity is of importance for applications in DNA based bio-dosimetry, data-storage, pharmaceutical quality-control, donor insemination and DNA based functional nanomaterials. Standard protocols for these applications involve repeated freeze-thaw cycles of the DNA, which can cause detrimental damage to the nucleobases, as well as the sugar-phosphate backbone and therefore the whole molecule. Throughout the literature three hypotheses can be found about the underlying mechanisms occurring during freeze-thaw cycles. It is hypothesized that DNA single-strand breaks during freezing can be induced by mechanical stress leading to shearing of the DNA molecule, by acidic pH causing damage through depurination and beta elimination or by the presence of metal ions catalyzing oxidative damage via reactive oxygen species (ROS). Here we test these hypotheses under well defined conditions with plasmid DNA pUC19 in high-purity buffer (1xPBS) at physiological salt and pH 7.4 conditions, under pH 6 and in the presence of metal ions in combination with the radical scavengers DMSO and Ectoine. The results show for the 2686 bp long plasmid DNA, that neither mechanical stress, nor pH 6 lead to degradation during repeated freeze-thaw cycles. In contrast, the presence of metal ions (Fe2+) leads to degradation of DNA via the production of radical species. KW - DNA KW - DNA stability KW - Pharmacy KW - Reference material KW - pUC19 KW - Strand break KW - SSB KW - Dosimetry KW - Biodosimetry KW - Biologisches Dosimeter KW - DNA Dosimeter KW - Quality control KW - Plasmid DNA KW - DNA data storage KW - Nucleobase KW - Base damage KW - Base loss KW - DNA degradation KW - Metal ions KW - ROS KW - OH radical KW - Fenton Reaction KW - H2O2 KW - DNA based data storage KW - Freezing KW - Thawing KW - Mechanical stress KW - pH KW - Beta elimination KW - Ectoine KW - Ectoin KW - THP(B) KW - Radical scavenger KW - DMSO KW - Buffer KW - lN2 KW - DNA vortexing KW - AGE KW - SYBR Gold KW - Gel electrophoresis KW - DNA long term storage KW - DNA reference material PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-557148 DO - https://doi.org/10.1002/cbic.202200391 SP - 1 EP - 9 PB - Wiley-VCH GmbH AN - OPUS4-55714 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ros-Lis, J.V. A1 - Martínez-Mánez, Ramon A1 - Sancenón, F. A1 - Soto, J. A1 - Spieles, Monika A1 - Rurack, Knut T1 - Aquaraines as reporter units: insights into their photophysics, protonation, and metal-ion coordination behaviour JF - Chemistry - A European journal KW - Dyes/pigments KW - Fluorescence KW - Metal ions KW - Protonation KW - Squaraines KW - Farbstoffe KW - Fluoreszenz KW - Metallionen KW - Protonierung PY - 2008 DO - https://doi.org/10.1002/chem.200800300 SN - 0947-6539 SN - 1521-3765 VL - 14 SP - 10101 EP - 10114 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-18444 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rurack, Knut A1 - Resch-Genger, Ute A1 - Senoner, Mathias A1 - Dähne, Siegfried T1 - A new fluorescence probe for trace metal ions: cation dependent spectroscopic properties JF - Journal of fluorescence KW - 2,2´-Bipyridyl-3,3´-diol KW - Metal ions KW - Cation dependence KW - Fluorescence probe PY - 1993 SN - 1053-0509 SN - 1573-4994 VL - 3 IS - 3 SP - 141 EP - 143 PB - Plenum Publ. Corp. CY - New York, NY AN - OPUS4-2105 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zhang, Zhiyang A1 - Merk, V. A1 - Müller, Anja A1 - Unger, Wolfgang A1 - Kneipp, Janina T1 - Role of metal cations in plasmon-catalyzed oxidation: A case study of p-aminothiophenol dimerization JF - ACS Catalysis N2 - The mechanism of the plasmon-catalyzed reaction of p-aminothiophenol (PATP) to 4,4′-dimercaptoazobenzene (DMAB) on the surface of metal nanoparticles has been discussed using data from surface-enhanced Raman scattering of DMAB. Oxides and hydroxides formed in a plasmon-catalyzed process were proposed to play a central role in the reaction. Here, we report DMAB formation on gold nanoparticles occurring in the presence of the metal cations Ag+, Au3+, Pt4+, and Hg2+. The experiments were carried out under conditions where formation of gold oxide or hydroxide from the nanoparticles can be excluded and at high pH where the formation of the corresponding oxidic species from the metal ions is favored. On the basis of our results, we conclude that, under these conditions, the selective oxidation of PATP to DMAB takes place via formation of a metal oxide from the ionic species in a plasmon-catalyzed process. By evidencing the necessity of the presence of the metal cations, the reported results underpin the importance of metal oxides in the reaction. KW - Metal ions KW - Plasmonic catalysis KW - p-aminothiophenol KW - 4,4'-dimercaptoazobenzene KW - Surface-enhanced Raman scattering PY - 2017 UR - http://pubs.acs.org/doi/abs/10.1021/acscatal.7b02700 DO - https://doi.org/10.1021/acscatal.7b02700 SN - 2155-5435 N1 - Geburtsname von Müller, Anja: Hermanns, A. - Birth name of Müller, Anja: Hermanns, A. VL - 7 IS - 11 SP - 7803 EP - 7809 PB - American Chemical Society CY - Washington AN - OPUS4-43001 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -