TY - JOUR A1 - Fischer, Tobias A1 - Dietrich, Paul A1 - Unger, Wolfgang A1 - Rurack, Knut T1 - Multimode surface functional group determination: combining steady-state and time-resolved fluorescence with X‑ray photoelectron spectroscopy and absorption measurements for absolute quantification N2 - The quantitative determination of surface functional groups is approached in a straightforward laboratory-based method with high reliability. The application of a multimode BODIPY-type fluorescence, photometry, and X-ray photoelectron spectroscopy (XPS) label allows estimation of the labeling ratio, i.e., the ratio of functional groups carrying a label after reaction, from the elemental ratios of nitrogen and fluorine. The amount of label on the surface is quantified with UV/vis spectrophotometry based on the molar absorption coefficient as molecular property. The investigated surfaces with varying density are prepared by codeposition of 3-(aminopropyl) triethoxysilane (APTES) and cyanoethyltriethoxysilane (CETES) from vapor. These surfaces show high functional group densities that result in significant fluorescence quenching of surface-bound labels. Since alternative quantification of the label on the surface is available through XPS and photometry, a novel method to quantitatively account for fluorescence quenching based on fluorescence lifetime (τ) measurements is shown. Due to the complex distribution of τ on high-density surfaces, the stretched exponential (or Kohlrausch) function is required to determine representative mean lifetimes. The approach is extended to a commercial Rhodamine B isothiocyanate (RITC) label, clearly revealing the problems that arise from such charged labels used in conjunction with silane surfaces. KW - surface group quantification KW - fluorescence spectroscopy KW - absorption spectroscopy KW - X-ray photoelectron spectroscopy KW - dyes PY - 2016 DO - https://doi.org/DOI: 10.1021/acs.analchem.5b03468 SN - 0003-2700 VL - 88 IS - 2 SP - 1210 EP - 1217 PB - American Chemical Society CY - Washington, DC AN - OPUS4-35832 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - 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 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 - Nöll, G. A1 - Daub, J. A1 - Lutz, M. A1 - Rurack, Knut T1 - Synthesis, spectroscopic properties, and electropolymerization of azulene dyads N2 - Four azulene dyads have been synthesized and studied by spectroscopic and electrochemical methods. A triarylamine, a boron-dipyrromethene (BDP or BODIPY), a porphyrin, and an isoalloxazine moiety have been linked to an extended π electron system at the 2-position of azulene, leading to the dyads 1–4, respectively. For the synthesis of 1–4, first 2-(4-ethynyl-phenyl)azulene (EPA) was prepared, which was further reacted with the halogenated chromophores by Pd-catalyzed cross-coupling reactions. The dyads 1–4 exhibit strong absorption bands in the visible range, which are dominated by the absorption spectra of the individual subchromophores. Fluorometric studies of 2–4 revealed that after excitation of the subchromophoric unit attached to the parent azulene moiety, quenching mainly through energy transfer to azulene is effective, whereas possible charge-transfer interactions play only a minor role. Potentiodynamic oxidation of the dyads 1–4 leads to the formation of polymer films, which are deposited at the electrode. The polymer film derived from 1 was further characterized by spectroelectrochemistry. During positive doping of poly-1, a strong absorption band appears at 13,200 cm–1, which is typical for triarylamine radical cations. This band is overlapping with a broad absorption band in the low-energy region that might be caused by charge-transfer interactions within the polymer. KW - Azulen KW - Elektropolymerisation KW - Energietransfer KW - Farbstoffe KW - Fluoreszenz PY - 2011 DO - https://doi.org/10.1021/jo200080v SN - 0022-3263 SN - 1520-6904 VL - 76 IS - 12 SP - 4859 EP - 4873 PB - American Chemical Society CY - Washington, DC AN - OPUS4-23987 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hecht, Mandy A1 - Fischer, Tobias A1 - Dietrich, Paul A1 - Kraus, Werner A1 - Descalzo López, Ana Belén A1 - Unger, Wolfgang A1 - Rurack, Knut T1 - Fluorinated Boron-Dipyrromethene (BODIPY) dyes: bright and versatile probes for surface analysis N2 - A family of bright boron-dipyrromethene-type fluorophores with a high number of fluorine atoms (F-BODIPYs) has been developed and characterized by X-ray crystallography and optical spectroscopy. The introduction of 3,5-bis(trifluoromethyl)phenyl and pentafluorophenyl moieties significantly enhances the photostability of such dyes, yielding for instance photostable near-infrared (NIR) fluorophores that show emission maxima>750 nm, when the BODIPY's π system is extended with two (dimethylamino)styryl and (dimethylamino)naphthastyryl moieties, or green-emitting BODIPYs with fluorescence quantum yields of unity. When equipped with a suitable group that selectively reacts for instance with amines, F-BODIPYs can be used as potent dual labels for the quantification of primary amino groups on surfaces by X-ray photoelectron spectroscopy (XPS) and fluorescence, two powerful yet complementary tools for the analysis of organic surface functional groups. The advantage of reactive F-BODIPYs is that they allow a fast and non-destructive mapping of the labelled supports with conventional fluorescence scanners and a subsequent quantification of selected areas of the same sample by the potentially traceable XPS technique. The performance is exemplarily shown here for the assessment of the amino group density on SiO2 supports, one of the most common reactive silica supports, in particular, for standard microarray applications. KW - Amino groups KW - Dyes KW - Fluorescence KW - Surface analysis KW - X-ray photoelectron spectroscopy KW - Amino-Gruppen KW - Farbstoffe KW - Fluoreszenz KW - Oberflächenanalytik KW - Röntgen-Photoelektronen-Spektroskopie PY - 2013 DO - https://doi.org/10.1002/open.201200039 SN - 2191-1363 VL - 2 IS - 1 SP - 25 EP - 38 PB - Wiley-VCH-Verl. CY - Weinheim AN - OPUS4-27783 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hecht, Mandy A1 - Kraus, Werner A1 - Rurack, Knut T1 - A highly fluorescent pH sensing membrane for the alkaline pH range incorporating a BODIPY dye N2 - A robust and re-usable dipstick-type fluorescent pH sensor for the alkaline pH range was developed by embedding a brightly fluorescent boron–dipyrromethene (BODIPY) dye bearing an acidic phenol moiety into a polyurethane matrix immobilized on a 3D epoxy-functionalized polymer support. The sensor strip has a dynamic working range of pH 10.0–13.1, i.e., operates in strongly basic media where pH glass electrodes can suffer from alkaline errors, and tolerates a high electrolyte background such as simulated seawater and sewage. This work describes the preparation of the sensing material and provides insight into the features that a hydrogel sensing membrane can bestow on an embedded pH-responsive dye by means of optical spectroscopic investigations. KW - pH-Wert KW - Farbstoffe KW - Fluoreszenz KW - Teststreifen KW - Hydrogel PY - 2013 DO - https://doi.org/10.1039/c2an35860c SN - 0003-2654 SN - 1364-5528 VL - 138 IS - 1 SP - 325 EP - 332 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-27638 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Biyikal, Mustafa A1 - Hecht, Mandy A1 - Martínez-Mánez, Ramon A1 - Rurack, Knut A1 - Sancenón, F. ED - Gale, P.A. ED - Steed, J.W. T1 - Supramolecular hybrid nanomaterials as prospective sensing platforms N2 - Supramolecular interactions are vital processes in many chemical sensors, biochemical assays, and other analytical detection schemes. On the background of the current, rapidly developing, and constantly changing requirements for (bio)analytical techniques, the classical molecular host is increasingly overburdened to accomplish a specific analytical task with the desired selectivity and sensitivity. Instead, other signaling strategies have to be conceived that overcome the limits in signal output, dynamic range, or compound targeting, which are imminent to various traditional methods. A very promising approach is the combination of concepts of supramolecular chemistry with nanostructured or nanoscopic inorganic materials, that is, the development of hybrid sensor materials. Such hybrids often lead to improved functionality and enhanced performance, and the present chapter discusses the contributory features in relation to the major aspects, which are related to the enhanced coordination by the preorganization of binding sites, signal amplification by the preorganization on surfaces, aggregation‐mediated signaling, surface‐modification‐based signaling, the tuning of selectivity through polarity and size, and gated signaling. KW - Supramolekulare Chemie KW - Optische Sonden KW - Nanotechnologie KW - Hybridmaterialien KW - Fluorescence KW - Hybrid nanomaterials KW - Optical sensors KW - Redox sensors KW - Supramolecular chemistry PY - 2012 SN - 978-0-470-74640-0 DO - https://doi.org/10.1002/9780470661345.smc199 SP - 3669 EP - 3698 PB - John Wiley & Sons AN - OPUS4-26118 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rurack, Knut T1 - Biological and Biomimetic Approaches toward the Detection of Nitro- and Peroxide-based Explosives T2 - International Workshop on Explosives Detection 2010 CY - Valencia, Spain DA - 2010-11-25 PY - 2010 AN - OPUS4-22869 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rurack, Knut T1 - Molecularly Imprinted Polymer Films as Sensory Materials for the Selective Detection of Carboxylates via Flourescence T2 - European Polymer Congress 2011(EPF) CY - Granada, Spain DA - 2011-06-26 PY - 2011 AN - OPUS4-23931 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rurack, Knut T1 - Organically functionalized mesopporous silica particles as a versatile platform for Hg2+ determination, sequestration and CH3Hg+ speciation witz simple analytical protocols T2 - ANAKON 2011 CY - Zurich, Switzerland DA - 2011-03-22 PY - 2011 AN - OPUS4-23936 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rurack, Knut T1 - Implementing Signal Amplification Features with Gated Mesoporous Sensory Hybrids for Methymercury Determination T2 - Hybrid Materials 2011 CY - Strasbourg, France DA - 2011-03-03 PY - 2011 AN - OPUS4-23935 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rurack, Knut T1 - Gated Fluorogenic Hybrid Sensor Materials with Inherent Signal Amplification T2 - 40 International Conference on Coordination Chemistry (ICCC40) CY - Valencia, Spain DA - 2012-09-09 PY - 2012 AN - OPUS4-26849 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rurack, Knut T1 - Test strip-based fluorescence detection of fluoride in aqueous media with a BODIPY-linked hydrogen bonding receptor T2 - International Conference on Photochemistry (ICP 2013) CY - Leuven, Belgium DA - 2013-07-21 PY - 2013 AN - OPUS4-28947 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Climent Terol, Estela A1 - Mondragón, L. A1 - Martínez-Mánez, Ramon A1 - Sancenón, F. A1 - Marcos, M. Dolores A1 - Murguía, J.R. A1 - Amorós, P. A1 - Rurack, Knut A1 - Pérez-Payá, E. T1 - Selektiver, hoch empfindlicher und schneller Nachweis genomischer DNA mit gesteuerten Materialien am Beispiel von Mycoplasma N2 - Mit DNA verschlossene und mit Farbstoff beladene mesoporöse Siliciumdioxid-Nanopartikel wurden zum Nachweis von Mycoplasma bis zu einer Nachweisgrenze von ca. 70 genomischen DNA-Kopien pro µL in real kontaminierten Zellkulturmedien ohne die Hilfe von PCR-Techniken eingesetzt. KW - DNA KW - Gesteuerte Materialien KW - Mesoporöse Träger KW - Mycoplasma KW - Sonden PY - 2013 DO - https://doi.org/10.1002/ange.201302954 SN - 0044-8249 SN - 0932-2140 SN - 1521-3757 VL - 125 IS - 34 SP - 9106 EP - 9110 PB - Wiley-VCH CY - Weinheim AN - OPUS4-28970 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rurack, Knut T1 - Gated Hybrid Sensor Materials for Amplified Fluorescence Sensing T2 - E-MRS 2013 Spring Meeting CY - Strasbourg, France DA - 2013-05-27 PY - 2013 AN - OPUS4-28949 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rurack, Knut T1 - Preparation of hybrid particle architectures for single microparticle-based detection in suspension arrays using FRET T2 - Tag der Chemie 2013 CY - Potsdam, Germany DA - 2013-06-27 PY - 2013 AN - OPUS4-28948 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gotor, Raúl A1 - Costero, A. M. A1 - Gil, S. A1 - Parra, M. A1 - Gavina, P. A1 - Rurack, Knut T1 - Boolean operations mediated by an ion-pair receptor of a multi-readout molecular logic gate N2 - A heteroditopic BODIPY dye that performs all basic Boolean operations with a cation (K+) and an anion (F-) as inputs and absorption, transmission and fluorescence as outputs is described. The molecular logic gate can also act as a digital comparator between the inputs. KW - Farbstoffe KW - Molekulare Gatter KW - Ionenpaare KW - Fluoreszenz KW - Boolsche Operationen PY - 2013 DO - https://doi.org/10.1039/c3cc45377d SN - 0022-4936 SN - 1359-7345 VL - 49 IS - 94 SP - 11056 EP - 11058 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-29507 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rurack, Knut T1 - Test strip-based fluorescence detection of fluoride in aqueous media with a BODIPY-linked hydrogen bonding receptor T2 - 26th International Conference on Photochemistry (ICP 2013) CY - Leuven, Belgium DA - 2013-07-21 PY - 2013 AN - OPUS4-29565 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rurack, Knut T1 - Long-wavelength Polymethine Dyes and Probes - Prospects, Pitfalls and Color Rules T2 - Control of Electronic Properties of Aggregated pi-Conjugated Molecules CY - Würzburg, Germany DA - 2013-07-11 PY - 2013 AN - OPUS4-29563 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rurack, Knut T1 - Responsive Dyes and Sensing Matrices: From Moleculary Imprinted Polymers to Nitrocellulose Membranes for Simple Fluorescence Assays T2 - Promotionsverteidigung CY - Santiago de Compostela, Spain DA - 2013-11-26 PY - 2013 AN - OPUS4-29631 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rurack, Knut T1 - Implementing Signal Generation Features in Organic Dyes T2 - Control of Electronic Properties of Aggregated pi-Conjugated Molecules CY - Würzburg, Germany DA - 2013-07-10 PY - 2013 AN - OPUS4-29564 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rurack, Knut T1 - Integrating Dyes with Sensing Matrices: Toward Simple yet Powerful Fluorescence Assays T2 - Gastvortrag, Department of Biomedical Sciences, Malmö University CY - Malmö, Sweden DA - 2014-04-02 PY - 2014 AN - OPUS4-30518 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -