TY - JOUR A1 - Hennig, Andreas A1 - Borcherding, H. A1 - Jäger, Christian A1 - Hatami, Soheil A1 - Würth, Christian A1 - Hoffmann, Angelika A1 - Hoffmann, Katrin A1 - Thiele, T. A1 - Schedler, U. A1 - Resch-Genger, Ute T1 - Scope and limitations of surface functional quantification methods: exploratory study with poly(acrylic acid)-grafted micro- and nanoparticles N2 - The amount of grafted poly(acrylic acid) on poly(methyl methacrylate) micro- and nanoparticles was quantified by conductometry, 13C solid-state NMR, fluorophore labeling, a supramolecular assay based on high-affinity binding of cucurbit[7]uril, and two colorimetric assays based on toluidine blue and nickel complexation by pyrocatechol violet. The methods were thoroughly validated and compared with respect to reproducibility, sensitivity, and ease of use. The results demonstrate that only a small but constant fraction of the surface functional groups is accessible to covalent surface derivatization independently of the total number of surface functional groups, and different contributing factors are discussed that determine the number of probe molecules which can be bound to the polymer surface. The fluorophore labeling approach was modified to exclude artifacts due to fluorescence quenching, but absolute quantum yield measurements still indicate a major uncertainty in routine fluorescence-based surface group quantifications, which is directly relevant for biochemical assays and medical diagnostics. Comparison with results from protein labeling with streptavidin suggests a porous network of poly(acrylic acid) chains on the particle surface, which allows diffusion of small molecules (cutoff between 1.6 and 6.5 nm) into the network. KW - Polymers KW - Surface groups KW - Quantification KW - Fluorescence PY - 2012 DO - https://doi.org/10.1021/ja302649g SN - 0002-7863 SN - 1520-5126 VL - 134 IS - 19 SP - 8268 EP - 8276 PB - American Chemical Society CY - Washington, DC AN - OPUS4-26002 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Resch-Genger, Ute A1 - Pfeifer, Dietmar A1 - Hoffmann, Katrin A1 - Flachenecker, Günter A1 - Hoffmann, Angelika A1 - Monte, C. ED - Resch-Genger, Ute ED - O.S. Wolfbeis, T1 - Linking fluorometry to radiometry with physical and chemical transfer standards: instrument characterization and traceable fluorescence measurements N2 - Problems associated with the measurement of photoluminescence are briefly reviewed, including relevant instrument parameters affecting these measurements. Procedures for the characterization of relevant instruments are discussed, focusing on spectrofluorometers, and fit-for-purpose methods including suitable standards are recommended. The aim here is to increase the awareness of the importance of reliable instrument characterization and to improve the comparability of measurements of photoluminescence. KW - Calibration KW - Emission standards KW - Fluorescence intensity standards KW - Fluorescence standards KW - Quality assurance KW - Spectral correction PY - 2008 SN - 978-3-540-75206-6 DO - https://doi.org/10.1007/4243_2008_054 SN - 1617-1306 N1 - Serientitel: Springer Series on Fluorescence – Series title: Springer Series on Fluorescence VL - 5 IS - Part II SP - 65 EP - 99 PB - Springer AN - OPUS4-18301 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pfeifer, Dietmar A1 - Hoffmann, Katrin A1 - Hoffmann, Angelika A1 - Monte, Christian A1 - Resch-Genger, Ute T1 - The Calibration Kit Spectral Fluorescence Standards - A Simple and Certified Tool for the Standardization of the Spectral Characteristics of Fluorescence Instruments N2 - With the Calibration Kit Spectral Fluorescence Standards BAM-F001–BAM-F005, we developed a simple tool for the characterization of the relative spectral responsivity and the long-term stability of the emission channel of fluorescence instruments under routine measurement conditions thereby providing the basis for an improved comparability of fluorescence measurements and eventually standardization. This first set of traceable fluorescence standards, which links fluorescence measurements to the spectral radiance scale in the spectral range of 300–770 nm and has been optimized for spectrofluorometers, can be employed for different measurement geometries and can be adapted to different fluorescence techniques with proper consideration of the underlying measurement principles. KW - Fluorescence KW - Standard KW - Spectral correction KW - Emission KW - Calibration tool PY - 2006 DO - https://doi.org/10.1007/s10895-006-0086-8 SN - 1053-0509 SN - 1573-4994 VL - 16 IS - 4 SP - 581 EP - 587 PB - Plenum Publ. Corp. CY - New York, NY AN - OPUS4-14206 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Resch-Genger, Ute A1 - Hoffmann, Katrin A1 - Hoffmann, Angelika T1 - Standardization of Fluorescence Measurements - Criteria for the Choice of Suitable Standards and Approaches to Fit-for-Purpose Calibration Tools N2 - This report summarizes problems associated with the comparability of measurements of photoluminescence and procedures for the characterization of relevant instruments, focusing on physical and chemical fluorescence standards. To provide recommendations on selecting and using such standards, we derive general and scope-specific requirements and quality criteria for suitable devices and materials and briefly address metrological requirements linked to the realization of comparable measurements. Special emphasis is dedicated to liquid and solid chromophore-based fluorescence standards developed or currently tested by us. KW - Fluorescence standard KW - Fluorescence spectroscopy KW - Spectral correction KW - day-to-day intensity standard KW - Calibration KW - Metrology KW - Fluorescence microscopy PY - 2008 DO - https://doi.org/10.1196/annals.1430.018 SN - 0077-8923 SN - 1749-6632 SN - 0094-8500 VL - 1130 SP - 35 EP - 43 PB - New York Academy of Sciences CY - New York, NY AN - OPUS4-17712 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Resch-Genger, Ute A1 - Hoffmann, Katrin A1 - Würth, Christian A1 - Behnke, Thomas A1 - Hoffmann, Angelika A1 - Pfeifer, Dietmar A1 - Engel, A. T1 - The toolbox of fluorescence standards: Flexible calibration tools for the standardization of fluorescence-based measurements N2 - To improve the reliability of fluorescence data in the life and material sciences and to enable accreditation of fluorescence techniques, standardization concepts are required that guarantee and improve the comparability of fluorescence measurements. At the core of such concepts are simple and evaluated fluorescence standards for the consideration of instrument-specific spectral and intensity distortions of measured signals and for instrument performance validation (IPV). Similarly in need are fluorescence intensity standards for the quantification from measured intensities and for signal referencing, thereby accounting for excitation light-induced intensity fluctuations. These standards should be preferably certified, especially for use in regulated areas like medical diagnostics. This encouraged us to develop liquid and solid standards for different fluorescence parameters and techniques for use under routine measurement conditions in different formates. Special emphasis was dedicated to the determination and control of the spectral responsivity of detection systems, wavelength accuracy, homogeneity of illumination, and intensity referencing for e.g. spectrofluorometers, fluorescence sensors and confocal laser scanning fluorescence microscopes. Here, we will present design concepts and examples for mono- and multifunctional fluorescence standards that provide traceability to radiometric units and present a first step towards a toolbox of standards. KW - Fluorescence KW - Fluorescence standard KW - Calibration tool KW - Spectral fluorescence standard KW - Intensity standard KW - Instrument performance validation KW - Quality assurance KW - Traceability KW - Glass KW - Liquid standard PY - 2010 DO - https://doi.org/10.1117/12.853133 SN - 0277-786X SN - 0038-7355 SN - 0361-0748 VL - 7666 IS - 76661J SP - 1 EP - 12 PB - Soc. CY - Redondo Beach, Calif. [u.a.] AN - OPUS4-21595 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoffmann, Katrin A1 - Dietzel, B. A1 - Schulz, B. A1 - Reck, Günter A1 - Hoffmann, Angelika A1 - Orgzall, I. A1 - Resch-Genger, Ute A1 - Emmerling, Franziska T1 - Combined structural and fluorescence studies of methyl-substituted 2,5-diphenyl-1,3,4-oxadiazoles - relation between electronic properties and packing motifs N2 - Prerequisite for the rational design of functional organic materials with tailor-made electronic properties is the knowledge of the structure–property relationship for the specific class of molecules under consideration. This encouraged us to systematically study the influence of the molecular structure and substitution pattern of aromatically substituted 1,3,4-oxadiazoles on the electronic properties and packing motifs of these molecules and on the interplay of these factors. For this purpose, seven diphenyl-oxadiazoles equipped with methyl substituents in the ortho- and meta-position(s) were synthesized and characterized. Absorption and fluorescence spectra in solution served here as tools to monitor substitution-induced changes in the electronic properties of the individual molecules whereas X-ray and optical measurements in the solid state provided information on the interplay of electronic and packing effects. In solution, the spectral position of the absorption maximum, the size of Stokes shift, and the fluorescence quantum yield are considerably affected by ortho-substitution in three or four ortho-positions. This results in blue shifted absorption bands, increased Stokes shifts, and reduced fluorescence quantum yields whereas the spectral position and vibrational structure of the emission bands remain more or less unaffected. In the crystalline state, however, the spectral position and shape of the emission bands display a strong dependence on the molecular structure and/or packing motifs that seem to control the amount of dye–dye-interactions. These observations reveal the limited value of commonly reported absorption and fluorescence measurements in solution for a straightforward comparison of spectroscopic results with single X-ray crystallography. This underlines the importance of solid state spectroscopic studies for a better understanding of the interplay of electronic effects and molecular order. KW - Diphenyl-oxadiazoles KW - X-ray structure KW - Packing motif KW - Optical properties KW - Fluorescence quantum yield PY - 2011 DO - https://doi.org/10.1016/j.molstruc.2010.11.071 SN - 0022-2860 SN - 1872-8014 SN - 0377-046X VL - 988 IS - 1-3 SP - 35 EP - 46 PB - Elsevier CY - Amsterdam AN - OPUS4-23253 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute A1 - Behnke, Thomas A1 - Brehm, Robert A1 - Grabolle, Markus A1 - Hennig, Andreas A1 - Hoffmann, Angelika A1 - Hoffmann, Katrin A1 - Linck, Lena A1 - Lochmann, Cornelia A1 - Pauli, Jutta A1 - Spieles, Monika A1 - Würth, Christian T1 - Funktionelle Chromophor-Systeme, innovative Validierungskonzepte und rückführbare Standards für die fluoreszenzbasierte multiparametrische Bioanalytik N2 - Unter dem Motto „Innovation und Qualitätssicherung in der (Bio)Analytik“ werden in der Arbeitsgruppe Fluoreszenzspektroskopie der BAM, Bundesanstalt für Materialforschung und -prüfung, funktionelle Chromophor-Systeme, einfache Signalverstärkungs- und Multiplexingstrategien sowie innovative Validierungs- und rückführbare Standardisierungskonzepte für verschiedene fluorometrische Messgrößen und Methoden entwickelt. Im Mittelpunkt stehen dabei molekulare Fluorophore, Nanokristalle mit größenabhängigen optischen Eigenschaften (sogenannte Quantenpunkte, QDs) und fluoreszierende Partikel variabler Größe sowie Sonden und Sensormoleküle für neutrale und ionische Analyte und für die Charakterisierung von funktionellen Gruppen. Dabei erfolgen auch methodische Entwicklungen für die Fluoreszenzspektroskopie, die Fluoreszenzmikroskopie, die Milcrofluorometrie, die Sensorik und die Mikroarraytechnologie. Ziele sind u. a. das Design und die Untersuchung von multiplexfähigen selektiven und sensitiven Sonden für die Biomarkeranalytik, die Entwicklung von Methoden zur Charakterisierung der signalrelevanten Eigenschaften dieser Chromophor-Systeme und zur Charakterisierung von funktionellen Gruppen an Oberflächen und ihre Validierung sowie die Entwicklung und Bereitstellung von formatadaptierbaren, flexibel ersetzbaren Standards für die fluoreszenzbasierte Multiparameteranalytik. T2 - 5. Senftenberger Innovationsforum Multiparameteranalytik CY - Senftenberg, Deutschland DA - 10.03.2011 KW - Multiparametric KW - Multiplexing KW - Fluorescence KW - Nanoparticles KW - NIR dyes KW - Surface analysis KW - Quantum yield KW - Quantum dot KW - Lifetime PY - 2011 SP - 86 EP - 108 CY - Senftenberg AN - OPUS4-23635 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lindner, G.-G. A1 - Hoffmann, Katrin A1 - Witke, Klaus A1 - Reinen, D. A1 - Heinemann, Chr. A1 - Koch, W. T1 - Spectroscopic Properties of Se2 2- and Se2- in Cancrinite KW - Selen KW - Cancrinit PY - 1996 SN - 0022-4596 SN - 1095-726X VL - 126 IS - 1 SP - 50 EP - 54 PB - Elsevier CY - San Diego, Calif. AN - OPUS4-690 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weh, K. A1 - Noack, M. A1 - Hoffmann, Katrin A1 - Schröder, K.-P. A1 - Caro, J. T1 - Change of gas permeation by photoinduced switching of zeolite-azobenzene membranes of type MFI and FAU N2 - FAU membranes of type Na–X and MFI membranes of type silicalite-1 which contain adsorbed azobenzene (AZB), have photoswitchable permeation properties due to the trans–cis photoisomerization of AZB. The change of gas permeation through these host–guest composite membranes depends on the irradiation wavelength, the quality of the membranes and the amount of adsorbed AZB. The permeances of the gases in the trans-form of the zeolite-encapsulated AZB were higher than those in the cis-form. The separation factors of equimolar mixtures of N2/CO2 and CH4/CO2 fed through the FAU–AZB membrane were higher at trans-switching than at cis-switching. The changes of the permeances of single gases and of the separation factors of equimolar gas mixtures by photoinduced trans–cis switching were found to be reversible over numerous switching cycles. The experimental results are in agreement with predictions made by Monte Carlo simulations for passing of permeant gases through these host–guest systems with the zeolite-hosted AZB in the trans- and in the cis-configuration. PY - 2002 DO - https://doi.org/10.1016/S1387-1811(02)00331-1 SN - 1387-1811 SN - 1873-3093 VL - 54 IS - 1-2 SP - 15 EP - 26 PB - Elsevier CY - Amsterdam AN - OPUS4-1752 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute A1 - Marlow, Frank T1 - Reversible Photosensitive Refractive Index Changes of Chromophor/Zeolite Nanocomposites T2 - Abschlußkolloquium "Nanostrukturierte Wirt/Gast-Systeme" CY - Berlin, Germany DA - 2002-10-21 PY - 2002 AN - OPUS4-1753 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Marlow, Frank A1 - Dong, W. A1 - Hoffmann, Katrin A1 - Loerke, J. ED - Schüth, F. T1 - Optically and electronically functional materials PY - 2002 SN - 3-527-30246-8 SP - 3029 EP - 3063 PB - Wiley-VCH CY - Weinheim AN - OPUS4-1751 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoffmann, Katrin A1 - Rurack, Knut A1 - Resch-Genger, Ute A1 - Marlow, Frank T1 - Absorption and Fluorescence Properties of Dyes Incorporated in Pores of AlPO4-5 T2 - 14. Deutsche Zeolith-Tagung CY - Frankfurt am Main, Germany DA - 2002-03-06 PY - 2002 AN - OPUS4-3261 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rurack, Knut A1 - Hoffmann, Katrin A1 - Al-Soufi, W. A1 - Resch-Genger, Ute T1 - 2,2'-Bipyridyl-3,3'-diol Incorporated into AlPO4-5 Crystals and Its Spectroscopic Properties as Related to Aqueous Liquid Media N2 - A novel fluorescent host-guest material, molecular sieves of AlPO4-5-type doped with 2,2'-bipyridyl-3,3'-diol, was prepared and spectroscopically characterized. The composite crystals show a pronounced optical anisotropy, indicating a high degree of alignment of the guest molecules within the zeolitic pore system. A mean tilting angle of 22 was found for the orientation of the individual dye molecules in the straight channels. The corrected fluorescence emission spectra were determined, and time-resolved fluorescence studies revealed that the dye molecules are preferentially found in three different types of microenvironment. By invoking pH-dependent studies of the dye in aqueous solution, we could trace these spectroscopic features back to two main influences, coadsorbed water within AlPO4-5 pores and guest-host interactions with a few relatively weak Brnsted acid (defect) sites of the inorganic host network. PY - 2002 DO - https://doi.org/10.1021/jp0259622 SN - 1520-6106 SN - 1520-5207 SN - 1089-5647 VL - 106 IS - 38 SP - 9744 EP - 9752 PB - Soc. CY - Washington, DC AN - OPUS4-1546 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Hoffmann, Katrin A1 - Marlow, F. ED - Auerbach, S. M. ED - Carrado, K. A. ED - Dutta, P. K. T1 - Molecular sieve-based materials for photonic applications PY - 2003 SN - 0-8247-4020-3 DO - https://doi.org/10.1201/9780203911167.ch18 SP - 921 EP - 949 PB - Dekker CY - New York AN - OPUS4-2713 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute A1 - Marlow, F. ED - Laeri, F. T1 - Photosensitive Optical Properties of Zeolitic Nanocomposites PY - 2003 SN - 3-527-30501-7 SP - 501 EP - 520 PB - Wiley-VCH CY - Weinheim AN - OPUS4-2714 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute A1 - Mix, Renate A1 - Friedrich, Jörg F. A1 - Nitschke, R. T1 - Characterization of Surface Functionalities of Plasma-modified Polymer Films by Fluorescence Spectroscopy and Microscopy T2 - ANAKON 2005 CY - Regensburg, Germany DA - 2005-03-15 PY - 2005 AN - OPUS4-7390 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute A1 - Mix, Renate A1 - Friedrich, Jörg F. A1 - Nitschke, R. T1 - Fluorescence Spectroscopic and Microscopic Studies on Plasmachemically Modified Polymer Films with Fluorophore-labeled Surface Functionalities T2 - MAF 9, 9th International Conference on Methods and Applications of Fluorescence CY - Lisbon, Portugal DA - 2005-09-04 PY - 2005 AN - OPUS4-7391 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute A1 - Nitschke, R. T1 - Simple Tool for the Standardization of Confocal Spectral Imaging Systems KW - Standards KW - Fluorescence reference material KW - Quality assurance KW - Fluorescence microscopy PY - 2005 SN - 1439-4243 SN - 1863-7809 VL - 7 IS - 3 SP - 18 EP - 19 PB - GIT-Verl. CY - Darmstadt AN - OPUS4-11070 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute A1 - Nitschke, R. T1 - Fluorescence standards for the characterization of the performance of spectral scanning fluorescence microscopes T2 - Focus on Microscopy 2006 CY - Perth, Australia DA - 2006-04-09 PY - 2006 AN - OPUS4-12067 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mix, Renate A1 - Hoffmann, Katrin A1 - Decker, Renate A1 - Friedrich, Jörg Florian A1 - Resch-Genger, Ute ED - Blasek, G. T1 - Möglichkeiten der kovalenten Anbindung von Funktionsmolekülen an Polymeroberflächen T2 - 13. Neues Dresdner Vakuumtechnisches Kolloquium "Beschichtung und Modifizierung von Kunststoffoberflächen" CY - Dresden, Deutschland DA - 2005-10-13 PY - 2005 SP - 35 EP - 41 PB - VDI-Verl. CY - Dresden AN - OPUS4-11946 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Resch-Genger, Ute A1 - Hoffmann, Katrin A1 - Nietfeld, W. A1 - Engel, A. A1 - Neukammer, J. A1 - Nitschke, R. A1 - Ebert, B. A1 - Macdonald, R. T1 - How to Improve Quality Assurance in Fluorometry: Fluorescence-Inherent Sources of Error and Suited Fluorescence Standards N2 - The scope of this paper is to illustrate the need for an improved quality assurance in fluorometry. For this purpose, instrumental sources of error and their influences on the reliability and comparability of fluorescence data are highlighted for frequently used photoluminescence techniques ranging from conventional macro- and microfluorometry over fluorescence microscopy and flow cytometry to microarray technology as well as in vivo fluorescence imaging. Particularly, the need for and requirements on fluorescence standards for the characterization and performance validation of fluorescence instruments, to enhance the comparability of fluorescence data, and to enable quantitative fluorescence analysis are discussed. Special emphasis is dedicated to spectral fluorescence standards and fluorescence intensity standards. KW - Fluorescence KW - Standard KW - Calibration KW - Microarray KW - In vivo imaging KW - Flow cytometry PY - 2005 DO - https://doi.org/10.1007/s10895-005-2630-3 SN - 1053-0509 SN - 1573-4994 VL - 15 IS - 3 SP - 337 EP - 362 PB - Plenum Publ. Corp. CY - New York, NY AN - OPUS4-10823 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Jörg Florian A1 - Kühn, Gerhard A1 - Mix, Renate A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute T1 - Tailoring of polymer surfaces with monotype functional groups of variable density using chemical and plasma chemical processes N2 - Polymer surfaces were modified in low-pressure glow discharge plasmas for introduction of monotype functional groups of different type and density. For this purpose three ways are selected, (i) oxygen plasma treatment followed by wet-chemical reduction of O functional groups to OH groups, (ii) plasma bromination for introducing C - Br groups and (iii) coating by deposition of thin plasma (co-) polymerized layers of functional groups-bearing monomers with OH, NH2, COOH, epoxy etc. functionalities. Subsequently, these groups were used as anchoring points for chemical grafting of spacer molecules, oligomers, prepolymers, fluorescent labels, ionic and nucleic acid residues, employing different chemical routes. The yield in monosort functional groups at polymer surfaces ranged from 10–14 (process i), 20–40 (process ii) and 18–31 groups per 100 C atoms (process iii) as measured by XPS after derivatization. The consumption of functional groups amounted to 40–90% of all functionalities present at the surface and depended on the dimensions of grafted molecules. For infinitely variably tuning the number of functional groups process iii was performed as copolymerization of a functional group-carrying comonomer with a non-functionalized (“chain-extending”) comonomer. KW - Introduction of functional groups KW - Plasma modification KW - Reactions at Polymer surfaces PY - 2006 SN - 0340-255x SN - 1437-8027 VL - 132 SP - 62 EP - 71 PB - Springer CY - Berlin AN - OPUS4-12515 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute A1 - Mix, Renate A1 - Friedrich, Jörg Florian T1 - Fluorescence Spectroscopic Studies on Plasma-Chemically Modified Polymer Surfaces with Fluorophore-Labeled Functionalities N2 - Molecular engineering of polymer surfaces that includes the attachment of functional molecules to existing or previously generated reactive chemical groups like e.g., - OH, - NH2, or - CHO requires simple strategies and tools for the controlled generation of surface functionalities and their derivatization as well as for their identification and eventually quantification. Here, we systematically investigate the plasma-chemical surface modification of polypropylene films in combination with dansyl labeling chemistry and conventional, yet costly, XPS and highly sensitive fluorescence spectroscopy for the detection of surface groups. Based on these results, the potential of and requirements on the fluorometric characterization and quantification of surfaces functionalities are discussed. KW - Fluorescence spectroscopy KW - Surface functionalization KW - Covalent labeling of polymer surfaces KW - Plasma modification KW - Fluorescent probe PY - 2006 DO - https://doi.org/10.1007/s10895-006-0076-x SN - 1053-0509 SN - 1573-4994 VL - 16 IS - 3 SP - 441 EP - 448 PB - Plenum Publ. Corp. CY - New York, NY AN - OPUS4-12560 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Descalzo López, Ana Belén A1 - Rurack, Knut A1 - Weißhoff, Hardy A1 - Martínez-Mánez, Ramon A1 - Marcos, M. Dolores A1 - Amorós, P. A1 - Hoffmann, Katrin A1 - Soto, J. T1 - Rational Design of a Chromo- and Fluorogenic Hybrid Chemosensor Material for the Detection of Long-Chain Carboxylates N2 - A strategy for the rational design of a new optical sensor material for the selective recognition of long-chain carboxylates in water is presented. The approach relies on the combination of structure-property relationships to single out the optimal molecular sensor unit and the tuning of the sensing characteristics of an inorganic support material. A spacer-substituted 7-urea-phenoxazin-3-one was employed as the signaling moiety and a mesoporous trimethylsilylated UVM-7 (MCM-41 type) material served as the solid support. The sensor material shows the advantageous features of both modules that is absorption and emission in the visible spectral range, a fluorescence red-shift and enhancement upon analyte coordination, and the amplification of noncovalent (binding) and hydrogen-bonding (recognition) interactions in the detection event. Besides these basic results that are related to the design and performance of the sensor material, the paper discusses general aspects of amido-substituted phenoxazinone photophysics and addresses some general features of molecular anion recognition chemistry in aqueous vs nonaqueous media, utilizing steady-state and time-resolved optical as well as NMR spectroscopies. Detailed studies on potentially competing biochemical species and a first access to the schematic model of the response of the sensor material as obtained by a combination of fluorescence lifetime distribution analysis and Langmuir-type fitting of the gross binding constants complement the key issues of the paper. KW - Chemosensor KW - Carboxylate KW - Rationales Design KW - Hybridmaterialien KW - Fluoreszenz PY - 2005 DO - https://doi.org/10.1021/ja045683n SN - 0002-7863 SN - 1520-5126 VL - 127 SP - 184 EP - 200 PB - American Chemical Society CY - Washington, DC AN - OPUS4-5985 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute A1 - Behnke, Thomas A1 - Drescher, D. A1 - Kneipp, J. T1 - Nanoparticles for FLIM-based Multiplexed Analysis and Imaging T2 - Focus on Microscopy (FOM 2013) CY - Maastricht, Netherlands DA - 2013-03-24 PY - 2013 AN - OPUS4-28470 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoffmann, Katrin A1 - Hoffmann, Angelika A1 - Spieles, Monika A1 - Resch-Genger, Ute T1 - Reference Standard for the performance validation of fluroescence measuring systems T2 - Life Science Day 2011 CY - Berlin, Germany DA - 2011-08-26 PY - 2011 AN - OPUS4-24520 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute A1 - Tannert, S. A1 - Kapusta, P. A1 - Glatz, A. A1 - Goschew, A. A1 - Ortmann, U. A1 - Erdmann, R. T1 - On the Spectral Sensitivity Calibration of Fluorescence Spectrometers: Extensions to the NIR, Polarization and Grating Effects T2 - 12th Conference on Methods and Applications of Fluorescence: Spectroscopy, Imaging and Probes (MAF-12) CY - Strasbourg, France DA - 2011-09-11 PY - 2011 AN - OPUS4-24521 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoffmann, Katrin A1 - Engel, A. A1 - Bäumle, M. A1 - Resch-Genger, Ute T1 - Characterization of highly fluorescence candidate glass references standards T2 - 12th Conference on Methods and Applicaions of Fluorescence: Spectroscopy, Imaging and Probes (MAF-12) CY - Strasbourg, France DA - 2011-09-11 PY - 2011 AN - OPUS4-24522 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Behnke, Thomas A1 - Laux, Eva-Maria A1 - Hoffmann, Katrin A1 - Peters, S. A1 - Haueisen, J. A1 - Klemm, M. A1 - Resch-Genger, Ute T1 - Simple approaches to fluorescence lifetime standards using dye-quencher pairs N2 - Photoluminescence techniques are amongst the most widely used tools in the material and life sciences, with new and exciting applications continuously emerging. Advantages include their comparative ease of use, unique sensitivity, non-invasive character, and potential for multiplexing, remote sensing, and miniaturization. Increasing applications of fluorescence techniques in the life sciences and emerging medical applications of fluorescence microscopic techniques including 1P and 2P fluorescence microscopy combined with fluorescence lifetime imaging (FLIM) in e.g. in vivo eye diagnostics boosted the demand for robust, easy-to-use, and reliable fluorescence standards to ensure the reliability and comparability of fluorescence data. This includes fluorescence standards for the consideration of instrument-specific spectral and intensity distortions of measured signals and instrument performance validation, fluorescence intensity standards for the quantification of measured intensities and for signal referencing, and lately, also fluorescence lifetime standards. T2 - BMT 2012 - 46. DGBMT Jahrestagung CY - Jena, Germany DA - 16.09.2012 PY - 2012 DO - https://doi.org/10.1515/bmt-2012-4499 SN - 0013-5585 SN - 1862-278X VL - 57 IS - Suppl. 1 SP - 613 PB - De Gruyter CY - Berlin AN - OPUS4-27682 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute A1 - Würth, Christian A1 - Koberling, F. A1 - Rüttinger, S. A1 - Tannert, S. A1 - Erdmann, R. T1 - Fast and Reliable Luminescence Quantum Yield Determination for efficient fluorescent Probes development T2 - SPIE BIOS 2013 - Part of Photonics West CY - San Francisco, CA, USA DA - 2013-02-02 PY - 2013 AN - OPUS4-27804 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute A1 - Behnke, Thomas A1 - Würth, Christian T1 - Rationally Designed NIR-Flourescent Nanoparticles for Bioanalytical Applications T2 - EUCheMS 2012 CY - Prague, Czech Republic DA - 2012-08-26 PY - 2012 AN - OPUS4-27807 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Resch-Genger, Ute A1 - Hoffmann, Katrin A1 - Monte, Christian A1 - Pfeifer, Dietmar T1 - Standards in Fluorescence Spectroscopy KW - Standard KW - Fluorescence KW - Reference material KW - Quality assurance KW - Spectrofluorometer PY - 2005 SN - 1434-2634 VL - 9 IS - 6 SP - 29 EP - 31 PB - GIT Verl. CY - Darmstadt AN - OPUS4-11556 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Engel, A. A1 - Ottermann, C. A1 - Klahn, J. A1 - Enseling, D. A1 - Korb, T. A1 - Resch-Genger, Ute A1 - Hoffmann, Katrin A1 - Schweizer, S. A1 - Selling, J. A1 - Kynast, U. A1 - Koberling, F. A1 - Rupertus, V. T1 - Fluorescence reference materials used for optical and biophotonic applications N2 - Fluorescence techniques are known for their high sensitivity and are widely used as analytical tools and detection methods for product and process control, material sciences, environmental and bio-technical analysis, molecular genetics, cell biology, medical diagnostics, and drug screening. According to DIN/ISO 17025 certified standards are used for fluorescence diagnostics having the drawback of giving relative values for fluorescence intensities only. Therefore reference materials for a quantitative characterization have to be related directly to the materials under investigation. In order to evaluate these figures it is necessary to calculate absolute numbers like absorption/excitation cross sections and quantum yield. This can be done for different types of dopands in different materials like glass, glass ceramics, crystals or nano crystalline material embedded in polymer matrices. Based on the optical spectroscopy data we will discuss options for characteristic doped glasses and glass ceramics with respect to scattering and absorption regime. It has shown recently for YAG:Ce glass ceramics that for a proper determination of the quantum efficiency in these highly scattering media a reference material with similar scattering and fluorescent properties is required. This may be performed using the emission decay measurement diagnostics, where the decay time is below 100 ns. In this paper we present first results of these aspects using well performing LUMOGEN RED organic pigments for a comparison of mainly transparent glass with glass ceramics doped with various amounts of dopands e.g. ions of raw earth elements and transition metals. The LUMOGEN red is embedded in silica and polyurethane matrices. Characterisations on wavelength accuracy and lifetime for different environmental conditions (temperature, UV irradiation) have been performed. Moreover intensity patterns and results for homogeneity, isotropy, photo and thermal stability will be discussed. In a next step we will show the transfer of the characterisation methods to inorganic fluophores (YAG:Ce) in silicon. Fluorescence (steady state, decay time) and absorption (remission, absorption) spectroscopy working in different temperature regimes (10 - 350 K) are employed diagnostic methods in order to get a microscopic view of the relevant physical processes and to prove the correctness of the obtained data. The work is funded by BMBF under project number 13N8849. KW - Fluorescence KW - Reference material KW - Glass KW - Glass ceramic KW - Phosphor KW - Doped glass KW - Glass ceramics PY - 2007 SN - 0-8194-6247-0 DO - https://doi.org/10.1117/12.728144 SN - 1605-7422 VL - 6628 SP - 662815-1 - 662815-9 AN - OPUS4-16729 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Martínez, R. A1 - Sancenón, F. A1 - Hoffmann, Katrin A1 - Rurack, Knut A1 - Descalzo López, Ana Belén T1 - Materiales híbridos en química analítica N2 - El desarrollo de receptores sintéticos complejos basados en conceptos de la química supramolecular no garantiza en ocasiones un reconocimiento molecular selectivo. Una alternativa en ciertos aspectos más simple y prometedora es el empleo de materiales híbridos orgánico-inorgánicos preparados mediante la funcionalización de sólidos inorgánicos porosos con receptores sintéticos adecuados. El anclaje de estos sistemas coordinantes a un soporte sólido da lugar a ciertos efectos sinérgicos que no están presentes ni en el material inicial ni en el receptor por separado y que sugieren que estos nuevos materiales híbridos pueden ser empleados en el desarrollo de nuevos sensores y nuevos protocolos de reconocimiento molecular y/o iónico. The development of synthetic receptors based in supramolecular chemistry concepts will no allow a selective molecular recognition. A more simple, convenient and innovative approach relies on the use of organic-inorganic hybrid materials. These hybrid materials will be prepared by the grafting of certain synthetic receptors onto porous inorganic solids. The grafting of these coordinating systems onto a solid support leads to synergic effects that are hardly achievable with only the synthetic receptors or the solids alone. The presence of these synergic effects suggests that these organic-inorganic hybrid materials will be used for the development of novel sensory systems and novel molecular and/or ionic recognitionprotocols. KW - Soportes inorgánicos KW - Receptores sintéticos KW - Materiales híbridos KW - Efectos sinérgicos KW - Química analítica KW - Inorganic supports KW - Synthetic receptors KW - Hybrid materials KW - Synergic effects KW - Analytical chemistry PY - 2007 SN - 1575-3417 VL - 103 IS - 4 SP - 22 EP - 27 PB - Springer AN - OPUS4-17512 LA - spa AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute A1 - Marlow, F. T1 - Reversible photosensitive refractive index changes of chromophore/zeolite nanocomposites T2 - Abschlusskolloquium des DFG-Schwerpunktprogramms "Nanoporöse Kristalle" CY - Berlin, Germany DA - 2002-10-21 PY - 2002 AN - OPUS4-10907 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rübner, Katrin A1 - Hoffmann, Dirk T1 - Characterization of mineral building materials by Mercury-Intrusion porosimetry N2 - Mineral building materials are generally heterogeneous and porous solids. Their engineering properties are closely associated with their porosity and pore-size distribution, which can be studied by mercury intrusion. The entire pore-size distribution curves are used to determine changes in the pore structure of a material class in a qualitative way. Certain parameters derived from pore-size distributions can be correlated to engineering properties. These key values are applied as criteria to evaluate the quality and durability of a building material. However, because of the heterogeneity of natural and artificial building materials and the influence of moisture content on their pore structure the results are strongly affected by preparation conditions such as sampling and drying. A correct analysis requires a knowledge of these effects. The paper describes the use of mercury porosimetry to study mineral building materials such as cementitious materials, bricks, and renderings. Furthermore, the influence of preparation effects on the precision of measurements is discussed. KW - Drying KW - Mercury-intrusion porosimetry KW - Mineral building material KW - Pore structure KW - Precision KW - Sampling PY - 2006 DO - https://doi.org/10.1002/ppsc.200601008 SN - 0934-0866 SN - 1521-4117 VL - 23 IS - 1 SP - 20 EP - 28 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-12640 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoffmann, Katrin A1 - Hoffmann, Angelika A1 - Pfeifer, Dietmar A1 - Monte, Christian T1 - Standardization of fluorescence techniques: Where do we stand and what do we need? T2 - National Physics Laboratory CY - London, England DA - 2006-06-26 PY - 2006 AN - OPUS4-12592 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute A1 - Mix, Renate A1 - Friedrich, Jörg F. A1 - Nitschke, R. T1 - Fluorescence microscopic and spetroscopic studies on functionalized polymer-supports labeled with amino sensitive fluorophores T2 - Focus on Microscopy (FoM) CY - Valencia, Spain DA - 2007-04-10 PY - 2007 AN - OPUS4-14864 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Mix, Renate A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute A1 - Decker, Renate A1 - Friedrich, Jörg Florian ED - Mittal, K. T1 - Covalent coupling of fluorophores to polymer surface-bonded functional groups KW - Plasma modification KW - Fluorescence KW - Surface functionalization KW - Reactions at polymer surfaces KW - Spectroscopy KW - Quantification PY - 2007 SN - 978-90-6764-453-2 VL - 4 SP - 171 EP - 191 PB - VSP CY - Utrecht AN - OPUS4-14867 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mix, Renate A1 - Hoffmann, Katrin A1 - Buschmann, H.-J. A1 - Friedrich, Jörg Florian A1 - Resch-Genger, Ute T1 - Anbindung von Fluoreszenzfarbstoffen an plasmachemisch funktionalisierte und Cucurbituril-modifizierte Oberflächen N2 - Plasmapolymerisierte Allylaminschichten (50 nm) wurden auf Polypropylenfolien abgeschieden. Die auf diese Weise generierte NH2-funktionalisierte Polymeroberfläche wurde mit Xanthen-Fluorophoren chemisch umgesetzt. Da die Farbstoff-gekoppelten Folien nur geringe Fluoreszenz aufwiesen, wurden zwei Wege zur möglichen Entkopplung der Farbstoffe von der Oberfläche und damit zur Erhöhung der Fluoreszenzintensität getestet. Als erstes wurde ein Spacer durch die Umsetzung der primären Aminogruppen mit Glutaraldehyd und der nachfolgenden Kettenverlängerung mit Diaminohexan eingeführt. Diese nachfolgende Reaktion ergab eine spacergebundene NH2-Oberfläche, die analog der Allylaminschicht mit den Farbstoffen umgesetzt wurde. Als weiterer Weg wurde der Zusatz einer geeigneten Käfigverbindung, des Cucurbit[6]urils, getestet. Die spacergebundenen und zusätzlich mit Cucurbituril modifizierten aminofunktionellen Oberflächen zeigten nach der Farbstoffankopplung eine verbesserte Fluoreszenzintensität. KW - Fluoreszenz KW - Spacer KW - Cucurbituril PY - 2007 DO - https://doi.org/10.1002/vipr.200700329 SN - 0947-076X SN - 1522-2454 VL - 19 IS - 5 SP - 31 EP - 37 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-16000 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Descalzo López, Ana Belén A1 - Hoffmann, Katrin A1 - Rurack, Knut A1 - Martínez-Mánez, Ramon A1 - Sancenón, F. T1 - Hybridmaterialien in der analytischen Chemie KW - Analytische Chemie KW - Hybridmaterialien KW - Sensorik KW - Fluoreszenz KW - Absorption KW - Mesoporöse Silicate KW - Goldnanopartikel KW - Quantenpunkte PY - 2007 SN - 1439-9598 SN - 1521-3854 VL - 55 IS - 02 SP - 124 EP - 129 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-16080 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoffmann, Katrin A1 - Mix, Renate A1 - Resch-Genger, Ute A1 - Friedrich, Jörg Florian T1 - Monitoring of Amino Functionalities on Plasma-Chemically Modified Polypropylene Supports with a Chromogenic and Fluorogenic Pyrylium Reporter N2 - A straightforward strategy toward the sensitive fluorometric detection of primary amino groups on plasma-chemically modified polypropylene supports is presented, exploiting the transformation of the sterically nonhindered pyrylium dye Py-1 into its pyridinium counterpart. The reaction-induced blue-shifted absorption and emission bands and an increased fluorescence quantum yield provide the basis for the spectroscopic distinction between covalently bound and free, that is, nonspecifically adsorbed label molecules. With this label, for the first time, plasma-chemically introduced amino functionalities could be monitored on the surface of a polymer film employing fluorescence spectroscopy and confocal laser scanning microscopy. KW - Fluorescence spectroscopy KW - Surface characterization KW - Covalent labeling KW - Plasma modification KW - Fluorescent label PY - 2007 UR - http://pubs.acs.org/cgi-bin/abstract.cgi/langd5/2007/23/i16/abs/la7004908.html SN - 0743-7463 SN - 1520-5827 VL - 23 IS - 16 SP - 8411 EP - 8416 PB - American Chemical Society CY - Washington, DC AN - OPUS4-15717 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoffmann, Katrin A1 - Mix, Renate A1 - Resch-Genger, Ute A1 - Friedrich, Jörg Florian T1 - Fluorescence Measurements on Functionalized Polymer Surfaces - Problems and Troubleshooting KW - Fluorescence spectroscopy KW - Polymer functionalization KW - Surface labeling KW - Pyrylium label PY - 2008 DO - https://doi.org/10.1196/annals.1430.015 SN - 0077-8923 SN - 1749-6632 SN - 0094-8500 VL - 1130 SP - 28 EP - 34 PB - New York Academy of Sciences CY - New York, NY AN - OPUS4-17567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute A1 - Engel, A. T1 - Glass-based Reference Standards for Fluorescence Applications T2 - XIII International Symposium on Luminescence Spectrometry CY - Bologna, Italy DA - 2008-09-07 PY - 2008 AN - OPUS4-18055 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Engel, A. A1 - Ottermann, C. A1 - Resch-Genger, Ute A1 - Hoffmann, Katrin A1 - Schweizer, S. A1 - Selling, J. A1 - Spaeth, J.-M. A1 - Rupertus, V. ED - Grzymala, R. ED - Haeberlé, O. T1 - Glass based fluorescence reference materials used for optical and biophotonic applications N2 - Fluorescence techniques are known for their high sensitivity and are widely used as analytical tools and detection methods for product and process control, material sciences, environmental and biotechnical analysis, molecular genetics, cell biology, medical diagnostics, and drug screening. For routine measurements by fluorescence techniques the existence of an improved quality assurance is one of the basic needs. According to DIN/ISO 17025 certified standards are used for fluorescence diagnostics having the drawback of giving relative values only. Typical requirements onto fluorescence reference materials or standards deal with the verification of the instrument performance as well as the improvement of the data comparability. Especially for biomedical applications fluorescence labels are used for the detection of proteins. In particular these labels consist of nano crystalline materials like CdS and CdSe. The field of Non-Cadmium containing materials is under investigation. In order to evaluate whether glass based materials can be used as standards it is necessary to calculate absolute values like absorption/excitation cross sections or relative quantum yields. This can be done using different quantities of dopands in glass, glass ceramics or crystals. The investigated materials are based on different types of glass, silicate, phosphate and boron glass, which play a dominant role for the absorption and emission mechanism. Additional to the so-called elementary fluorescence properties induced by raw earth elements the formation of defects lead to higher cross sections additionally. The main investigations deal with wavelength accuracy and lifetime of doped glasses, glass ceramics and crystalline samples. Moreover intensity patterns, homogeneity aspects and photo stability will be discussed. KW - Fluorescence KW - Reference material KW - Glass KW - Glass ceramics KW - Biophotonic KW - Multiplexing PY - 2006 DO - https://doi.org/10.1117/12.663627 SN - 1605-7422 VL - 6191 SP - 619110-1-619110-10 AN - OPUS4-14429 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute A1 - Mix, Renate A1 - Friedrich, Jörg F. T1 - Fluorescence studies on functionalized polypropylene supports using an amino-sensitive fluorogenic pyrylium T2 - Method and Application of Fluorescence (MAF10) CY - Salzburg, Austria DA - 2007-09-09 PY - 2007 AN - OPUS4-16409 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute A1 - Engel, A. T1 - Glass-based reference standards for fluorescence applications KW - Fluorescence standard KW - Luminophore-doped glass KW - Reference material KW - Instrument qualification PY - 2008 SN - 1522-7235 SN - 1099-1271 SN - 1522-7243 VL - 23 SP - 229 EP - 230 PB - Wiley CY - Chichester AN - OPUS4-18256 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Descalzo López, Ana Belén A1 - Martínez-Mánez, Ramon A1 - Sancenón, F. A1 - Hoffmann, Katrin A1 - Rurack, Knut T1 - Die supramolekulare Chemie organisch-anorganischer Hybrid-Nanomaterialien N2 - Die Entwicklung von Hybridmaterialien mit stark verbesserten Funktionen gelingt durch die Kombination geeigneter Nanomaterialien als Träger mit Motiven aus der supramolekularen Chemie. Diese hetero-supramolekularen Konzepte bieten vielfältige Möglichkeiten, die Lücken zwischen der Molekülchemie, Materialwissenschaften und Nanotechnologie zu schließen. Im Hinblick auf funktionelle Aspekte wurden in jüngster Zeit wichtige Fortschritte erzielt, z. B. verbesserte Erkennungs- und Sensoreigenschaften durch die Anordnung von Molekülen auf vororganisierten Oberflächen, der reversible Aufbau von nanometergroßen Netzwerken und dreidimensionalen Strukturen oder biomimetische und gesteuerte chemische Prozesse in Hybrid-Nanomaterialien, die als Grundlage für hoch spezialisierte Protokolle in dreidimensionalen Gerüststrukturen dienen können. Diese Ansätze ermöglichen eine Feinabstimmung der Eigenschaften von Nanomaterialien und eröffnen neue Perspektiven für die Anwendung supramolekularer Konzepte. KW - Supramolekulare Chemie KW - Anorganisch-organische Hybridmaterialien KW - Sensorik KW - Molekulare Maschinen KW - Aggregation KW - Mesoporöse Materialien KW - Molekulare Erkennung KW - Nanopartikel KW - Sensoren PY - 2006 DO - https://doi.org/10.1002/ange.200600734 SN - 0044-8249 SN - 0932-2140 SN - 1521-3757 VL - 118 IS - 36 SP - 6068 EP - 6093 PB - Wiley-VCH CY - Weinheim AN - OPUS4-12821 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Descalzo López, Ana Belén A1 - Martínez-Mánez, Ramon A1 - Sancenón, F. A1 - Hoffmann, Katrin A1 - Rurack, Knut T1 - The Supramolecular Chemistry of Organic-Inorganic Hybrid Materials N2 - The combination of nanomaterials as solid supports and supramolecular concepts has led to the development of hybrid materials with improved functionalities. These hetero-supramolecular ideas provide a means of bridging the gap between molecular chemistry, materials sciences, and nanotechnology. In recent years, relevant examples have been reported on functional aspects, such as enhanced recognition and sensing by using molecules on preorganized surfaces, the reversible building of nanometer-sized networks and 3D architectures, as well as biomimetic and gated chemistry in hybrid nanomaterials for the development of advanced functional protocols in three-dimensional frameworks. This approach allows the fine-tuning of the properties of nanomaterials and offers new perspectives for the application of supramolecular concepts. KW - Aggregation KW - Mesoporous materials KW - Molecular recognition KW - Nanoparticles KW - Sensors PY - 2006 DO - https://doi.org/10.1002/anie.200600734 SN - 1433-7851 SN - 1521-3773 SN - 0570-0833 VL - 45 IS - 36 SP - 5924 EP - 5948 PB - Wiley-VCH CY - Weinheim AN - OPUS4-12824 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Felbeck, Tom A1 - Behnke, Thomas A1 - Hoffmann, Katrin A1 - Grabolle, Markus A1 - Lezhnina, M.M. A1 - Kynast, U.H. A1 - Resch-Genger, Ute T1 - Nile-red-nanoclay hybrids: Red emissive optical probes for use in aqueous dispersion N2 - Water-dispersible and (bio)functionalizable nanoclays have a considerable potential as inexpensive carriers for organic molecules like drugs and fluorophores. Aiming at simple design strategies for red-emissive optical probes for the life sciences from commercial precursors with minimum synthetic effort, we systematically studied the dye loading behavior and stability of differently functionalized laponites. Here, we present a comprehensive study of the absorption and emission properties of the red emissive hydrophobic and neutral dye Nile Red, a well-known polarity probe, which is almost insoluble and nonemissive in water. Adsorption of this probe onto disk-shaped nanoclays was studied in aqueous dispersion as function of dye concentration, in the absence and presence of the cationic surfactant cetyltrimethylammonium bromide (CTAB) assisting dye loading, and as a function of pH. This laponite loading strategy yields strongly fluorescent nanoclay suspensions with a fluorescence quantum yield of 0.34 at low dye loading concentration. The dye concentration-, CTAB-, and pH-dependent absorption, fluorescence emission, and fluorescence excitation spectra of the Nile-Red6#8211;nanoclay suspensions suggest the formation of several Nile Red species including emissive Nile Red monomers facing a polar environment, nonemissive H-type dimers, and protonated Nile Red molecules that are also nonfluorescent. Formation of all nonemissive Nile Red species could be suppressed by modification of the laponite with CTAB. This underlines the great potential of properly modified and functionalized laponite nanodisks as platform for optical probes with drug delivery capacities, for example, for tumor and therapy imaging. Moreover, comparison of the Nile Red dimer absorption spectra with absorption spectra of previously studied Nile Red aggregates in dendrimer systems and micelles and other literature systems reveals a considerable dependence of the dimer absorption band on microenvironment polarity which has not yet been reported so far for H-type dye aggregates. KW - Nile Red KW - Dye KW - Laponite KW - Nanoclay KW - Photoluminescence KW - Fluorescence KW - Polarity probe KW - Aggregate KW - Dimer PY - 2013 UR - http://pubs.acs.org/doi/pdf/10.1021/la402165q DO - https://doi.org/10.1021/la402165q SN - 0743-7463 SN - 1520-5827 VL - 29 IS - 36 SP - 11489 EP - 11497 PB - American Chemical Society CY - Washington, DC AN - OPUS4-29017 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -