TY - JOUR A1 - Mackie, I.D. A1 - Röhrling, J. A1 - Gould, R.O. A1 - Pauli, Jutta A1 - Jäger, Christian A1 - Walkinshaw, M. A1 - Potthast, A. A1 - Rosenau, Th. A1 - Kosma, P. T1 - Crystal and molecular structure of methyl 4-O-methyl-beta-D-glucopyranosyl-(1->4)-beta-D-glucopyranoside N2 - The cellulose model compound methyl 4-O-methyl-?-Image-glucopyranosyl-(1?4)-?-Image-glucopyranoside (6) was synthesised in high overall yield from methyl ?-Image-cellobioside. The compound was crystallised from methanol to give colourless prisms, and the crystal structure was determined. The monoclinic space group is P21 with Z=2 and unit cell parameters a=6.6060 (13), b=14.074 (3), c=9.3180 (19) Å, ?=108.95(3)°. The structure was solved by direct methods and refined to R=0.0286 for 2528 reflections. Both glucopyranoses occur in the 4C1 chair conformation with endocyclic bond angles in the range of standard values. The relative orientation of both units described by the interglycosidic torsional angles [? (O-5?---C-1?---O-4---C-4) -89.1°, phi (C-1?---O-4---C-4---C-5) -152.0°] is responsible for the very flat shape of the molecule and is similar to those found in other cellodextrins. Different rotamers at the exocyclic hydroxymethyl group for both units are present. The hydroxymethyl group of the terminal glucose moiety displays a gauche–trans orientation, whereas the side chain of the reducing unit occurs in a gauche–gauche conformation. The solid state 13C NMR spectrum of compound 6 exhibits all 14 carbon resonances. By using different cross polarisation times, the resonances of the two methyl groups and C-6 carbons can easily be distinguished. Distinct differences of the C-1 and C-4 chemical shifts in the solid and liquid states are found. KW - Crystal structure KW - Cellulose KW - Methyl cellobioside KW - Solid state NMR PY - 2002 DO - https://doi.org/10.1016/S0008-6215(01)00299-3 SN - 0008-6215 SN - 1873-426X VL - 337 IS - 2 SP - 161 EP - 166 PB - Elsevier CY - Amsterdam AN - OPUS4-11023 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dreßler, Martin A1 - Nofz, Marianne A1 - Malz, Frank A1 - Pauli, Jutta A1 - Jäger, Christian A1 - Reinsch, Stefan A1 - Scholz, G. T1 - Aluminum speciation and thermal evolution of aluminas resulting from modified Yoldas sols N2 - Aluminas resulting from sols prepared via a modified Yoldas procedure were studied with differential thermal analysis (DTA), differential thermal gravimetrie (DTG), 27Al nuclear magnetic resonance (27Al MAS NMR) and X-ray diffraction (XRD) concerning their thermal properties, aluminum speciation and phase content. Hydrolysis of aluminum-sec-butoxide in aluminum nitrate solutions allowed to prepare stable sols with varying NO3-/Al molar ratios, solids contents and pH values. Resulting sols contained different aluminum species including also Al13 polycations. Sol preparation conditions also determined aluminum speciation in solid products obtained after thermal treatments of gels obtained from these sols. Al13 polycations and AlO5 species were found to play an important role for thermally induced transformation from amorphous products via eta-Al2O3 to alpha-Al2O3. Intermediately formed eta-Al2O3 promotes the phase transformation to alpha-Al2O3. KW - Alumina KW - Modified Yoldas sols KW - 27Al nuclear magnetic resonance KW - Differential thermal analysis KW - X-ray diffraction PY - 2007 DO - https://doi.org/10.1016/j.jssc.2007.06.018 SN - 0022-4596 SN - 1095-726X VL - 180 IS - 9 SP - 2409 EP - 2419 PB - Elsevier CY - San Diego, Calif. AN - OPUS4-16189 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian A1 - Pauli, Jutta A1 - Berger, Georg A1 - Spitzer, Andrea T1 - Entwicklung neuartiger Knochenersatzwerkstoffe und strukturelle Charakterisierung mittels der 31P-NMR-Spektroskopie T2 - Tagung "Tag der Chemie" CY - Berlin, Deutschland DA - 2002-12-04 PY - 2002 AN - OPUS4-1900 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute A1 - Würth, Christian A1 - Pauli, Jutta A1 - Weigert, Florian T1 - Quantitative optical-spectroscopic characterization of luminescent nanomaterials - Photoluminescence Quantum Yields N2 - Accurate and quantitative photoluminescence measurements are mandatory for the comparison of different emitter classes and the rational design of the next generation of molecular and nanoscale reporters as well as for most applications relying on their luminescence features in the life and material sciences and nanobiophotonics. In the following, procedures for the determination of the spectroscopic key parameter photoluminescence quantum yield, i.e., the number of emitted per absorbed photons, in the UV/vis/NIR/SWIR are presented including pitfalls and achievable uncertainties and material-specific effects related to certain emitter classes are addressed. Special emphasis is dedicated to luminescent nanocrystals. T2 - International Workshop on "Emerging Nanomaterials for Displays and SSL" CY - Dresden, Germany DA - 11.11.2021 KW - Nano KW - Nanomaterial KW - Nanocrystal KW - Semiconductor quantum dot KW - Lanthanide KW - Photoluminescence KW - Quantum yield KW - Photophysics KW - Lifetime KW - Surface chemistry KW - Brightness KW - NIR KW - SWIR KW - Method KW - Uncertainty KW - Rreference material PY - 2021 AN - OPUS4-53783 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schoetz, U. A1 - Deliolanis, N.C. A1 - Ng, D. A1 - Pauli, Jutta A1 - Resch-Genger, Ute A1 - Kühn, E. A1 - Heuer, S. A1 - Beisker, W. A1 - Köster, R.W. A1 - Zitzelsberger, H. A1 - Caldwell, R.B. T1 - Usefulness of a Darwinian system in a biotechnological application: evolution of optical window fluorescent protein variants under selective pressure N2 - With rare exceptions, natural evolution is an extremely slow process. One particularly striking exception in the case of protein evolution is in the natural production of antibodies. Developing B cells activate and diversify their immunoglobulin (Ig) genes by recombination, gene conversion (GC) and somatic hypermutation (SHM). Iterative cycles of hypermutation and selection continue until antibodies of high antigen binding specificity emerge (affinity maturation). The avian B cell line DT40, a cell line which is highly amenable to genetic manipulation and exhibits a high rate of targeted integration, utilizes both GC and SHM. Targeting the DT40's diversification machinery onto transgenes of interest inserted into the Ig loci and coupling selective pressure based on the desired outcome mimics evolution. Here we further demonstrate the usefulness of this platform technology by selectively pressuring a large shift in the spectral properties of the fluorescent protein eqFP615 into the highly stable and advanced optical imaging expediting fluorescent protein Amrose. The method is advantageous as it is time and cost effective and no prior knowledge of the outcome protein's structure is necessary. Amrose was evolved to have high excitation at 633 nm and excitation/emission into the far-red, which is optimal for whole-body and deep tissue imaging as we demonstrate in the zebrafish and mouse model. KW - Fluorescent protein KW - Quantum yield PY - 2014 DO - https://doi.org/10.1371/journal.pone.0107069 SN - 1932-6203 VL - 9 IS - 9 SP - e107069-1 EP - e107069-12 PB - PubMed Central AN - OPUS4-31976 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pauli, Jutta A1 - Licha, K. A1 - Berkemeyer, Janis Manuel A1 - Grabolle, Markus A1 - Spieles, Monika A1 - Wegner, N. A1 - Welker, P. A1 - Resch-Genger, Ute T1 - New fluorescent labels with tunable hydrophilicity for the rational design of bright optical probes for molecular imaging N2 - The rational design of bright optical probes and dye–biomolecule conjugates in the NIR-region requires fluorescent labels that retain their high fluorescence quantum yields when bound to a recognition unit or upon interaction with a target. Because hydrophilicity-controlled dye aggregation in conjunction with homo-FRET presents one of the major fluorescence deactivation pathways in dye–protein conjugates, fluorescent labels are required that enable higher labeling degrees with minimum dye aggregation. Aiming at a better understanding of the factors governing dye–dye interactions, we systematically studied the signal-relevant spectroscopic properties, hydrophilicity, and aggregation behavior of the novel xS-IDCC series of symmetric pentamethines equipped with two, four, and six sulfonic acid groups and selected conjugates of these dyes with IgG and the antibody cetuximab (ctx) directed against the cancer-related epidermal growth factor (EGF) receptor in comparison to the gold standard Cy5.5. With 6S-IDCC, which displays a molar absorption coefficient of 190 000 M–1 cm–1 and a fluorescence quantum yield (Φf) of 0.18 in aqueous media like PBS and nearly no aggregation, we could identify a fluorophore with a similarly good performance as Cy5.5. Bioconjugation of 6S-IDCC and Cy5.5 yielded highly emissive targeted probes with comparable Φf values of 0.29 for a dye-to-protein (D/P) ratio <1 and a reduced number of protein-bound dye aggregates in the case of 6S-IDCC. Binding studies of the ctx conjugates of both dyes performed by fluorescence microscopy and FACS revealed that the binding strength between the targeted probes and the EGF receptor at the cell membrane is independent of D/P ratio. These results underline the importance of an application-specific tuning of dye hydrophilicity for the design of bright fluorescent reporters and efficient optical probes. Moreover, we could demonstrate the potential of fluorescence spectroscopy to predict the size of fluorescence signals resulting for other fluorescence techniques such as FACS. KW - Cyanine KW - Cetuximab KW - IgG KW - Protein labeling KW - Fluorescence quantum yield KW - Hydrophilicity KW - Dimerization constant PY - 2013 DO - https://doi.org/10.1021/bc4000349 SN - 1043-1802 SN - 1520-4812 VL - 24 IS - 7 SP - 1174 EP - 1185 CY - Washington, DC AN - OPUS4-29076 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauli, Jutta T1 - Brilliant and Functional Herceptin Conjugates with a Remarkably High Number of Bound Fluorophores T2 - MOBI 2013 CY - Heidelberg, Germany DA - 2013-10-28 PY - 2013 AN - OPUS4-29576 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Würth, Christian A1 - Grabolle, Markus A1 - Pauli, Jutta A1 - Spieles, Monika A1 - Resch-Genger, Ute T1 - Relative and absolute determination of fluorescence quantum yields of transparent samples N2 - Luminescence techniques are among the most widely used detection methods in the life and material sciences. At the core of these methods is an ever-increasing variety of fluorescent reporters (i.e., simple dyes, fluorescent labels, probes, sensors and switches) from different fluorophore classes ranging from small organic dyes and metal ion complexes, quantum dots and upconversion nanocrystals to differently sized fluorophore-doped or fluorophore-labeled polymeric particles. A key parameter for fluorophore comparison is the fluorescence quantum yield (Φf), which is the direct measure for the efficiency of the conversion of absorbed light into emitted light. In this protocol, we describe procedures for relative and absolute determinations of Φf values of fluorophores in transparent solution using optical methods, and we address typical sources of uncertainty and fluorophore class-specific challenges. For relative determinations of Φf, the sample is analyzed using a conventional fluorescence spectrometer. For absolute determinations of Φf, a calibrated stand-alone integrating sphere setup is used. To reduce standard-related uncertainties for relative measurements, we introduce a series of eight candidate quantum yield standards for the wavelength region of ~350–950 nm, which we have assessed with commercial and custom-designed instrumentation. With these protocols and standards, uncertainties of 5–10% can be achieved within 2 h. PY - 2013 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-294202 DO - https://doi.org/10.1038/nprot.2013.087 SN - 1754-2189 SN - 1750-2799 VL - 8 IS - 8 SP - 1535 EP - 1550 PB - Nature Publishing Group CY - Basingstoke AN - OPUS4-29420 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Würth, Christian A1 - Lochmann, Cornelia A1 - Spieles, Monika A1 - Pauli, Jutta A1 - Hoffmann, Katrin A1 - Schüttrigkeit, T. A1 - Franzl, T. A1 - Resch-Genger, Ute T1 - Evaluation of a commercial integrating sphere setup for the determination of absolute photoluminescence quantum yields of dilute dye solutions N2 - The commercial availability of stand-alone setups for the determination of absolute photoluminescence quantum yields (φf) in conjunction with the increasing use of integrating sphere accessories for spectrofluorometers is expected to have a considerable influence not only on the characterization of chromophore systems for use in optical and opto-electronic devices, but also on the determination of this key parameter for (bio)analytically relevant dyes and functional luminophores. Despite the huge potential of systems measuring absolute φf values and the renewed interest in dependable data, evaluated protocols for even the most elementary case, the determination of the fluorescence quantum yield of transparent dilute solutions of small organic dyes with integrating sphere methods, are still missing. This encouraged us to evaluate the performance and sources of uncertainty of a simple commercial integrating sphere setup with dilute solutions of two of the best characterized fluorescence quantum yield standards, quinine sulfate dihydrate and rhodamine 101, strongly differing in spectral overlap between absorption and emission. Special attention is dedicated to illustrate common pitfalls of this approach, thereby deriving simple procedures to minimize measurement uncertainties and improve the comparability of data for the broad community of users of fluorescence techniques. KW - Lifetime KW - Fluorescence KW - Luminescence KW - Quantum yield KW - Quantum efficiency KW - Integrating sphere KW - Reabsorption KW - Rhodamine 101 KW - Quinine sulfate dihydrate KW - Method KW - Photoluminescence KW - Standard KW - Emission KW - Spectral correction KW - Excitation KW - Anisotropy PY - 2010 DO - https://doi.org/10.1366/000370210791666390 SN - 0003-7028 SN - 1943-3530 VL - 64 IS - 7 SP - 733 EP - 741 PB - Society for Applied Spectroscopy CY - Frederick, Md. AN - OPUS4-22089 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pauli, Jutta A1 - Brehm, Robert A1 - Spieles, Monika A1 - Kaiser, W.A. A1 - Hilger, I. A1 - Resch-Genger, Ute T1 - Novel fluorophores as building blocks for optical probes for in vivo near infrared fluorescence (NIRF) imaging N2 - Aiming at the identification of new fluorescent reporters for targeted optical probes, we assessed the application-relevant features of a novel asymmetric cyanine, DY-681, in comparison to the only clinically approved dye indocyanine green (ICG), the golden imaging standard Cy5.5, and the asymmetric cyanine DY-676 successfully exploited by us for the design of different contrast agents. This comparison included the analysis of the spectroscopic properties of the free fluorophores and their thermal stability in aqueous solution as well as their cytotoxic potential. In addition, the absorption and emission features of IgG-conjugated DY-681 were examined. The trimethine DY-681 exhibited spectral features closely resembling that of the pentamethine Cy5.5. Its high thermal stability in phosphate buffer saline (PBS) solution in conjunction with its low cytotoxicity, reaching similar values as determined for Cy5.5 and DY-676, renders this dye more attractive as ICG and, due to its improved fluorescence quantum yield in PBS, also superior to DY-676. Although in PBS, Cy5.5 was still more fluorescent, the fluorescence quantum yields (Φf) of DY-681 and Cy5.5 in PBS containing 5 mass-% bovine serum albumin (BSA) were comparable. Labeling experiments with DY-681 and the model antibody IgG revealed promisingly high Φf values of the bioconjugated dye. KW - Fluorescence KW - Cyanine dye KW - Cytotoxicity KW - Stability KW - In vivo fluorescence imaging KW - Quantum yield KW - Contrast agent KW - Optical probe PY - 2010 DO - https://doi.org/10.1007/s10895-010-0603-7 SN - 1053-0509 SN - 1573-4994 VL - 20 IS - 3 SP - 681 EP - 693 PB - Plenum Publ. Corp. CY - New York, NY AN - OPUS4-21401 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -