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 - Ahiboz, D. A1 - Andresen, Elina A1 - Manley, P. A1 - Resch-Genger, Ute A1 - Würth, Christian A1 - Becker, C. T1 - Metasurface-Enhanced Photon Upconversion upon 1550 nm Excitation N2 - Photon upconversion upon 1550 nm excitation is of high relevance for applications in the third biological excitation window, for photovoltaics beyond current limitations, and enables appealing options in the field of glass Fiber telecommunications. Trivalent doped erbium ions (Er3+) are the material of choice for 1550 nm excited upconversion, however, they suffer from a low absorption cross-section and a low brightness. Therefore, the ability of Silicon metasurfaces to provide greatly enhanced electrical near-fields is employed to enable efficient photon upconversion even at low external Illumination conditions. Hexagonally shaped β-NaYF4:Er3+ nanoparticles are placed on large-area silicon metasurfaces designed to convert near-infrared (1550 nm) to visible light. More than 2400-fold enhanced photon upconversion luminescence is achieved by using this metasurface instead of a planar substrate. With the aid of optical simulations based on the finite-element method, this result is attributed to the coupling of the excitation source with metasurface resonances at appropriate incident angles. Analysis of the excitation power density dependence of upconversion luminescence and red-to-green-emission ratios enables the estimation of nanoscale near-field enhancement on the metasurface. The findings permit the significant reduction of required external excitation intensities for photon upconversion of 1550 nm light, opening perspectives in biophotonics, telecommunication, and photovoltaics. KW - Nano KW - Nanomaterial KW - Upconversion nanoparticle KW - Lanthanide KW - Photoluminescence KW - Quantum yield KW - Photophysics KW - Lifetime KW - Sensor KW - Excitation power density KW - Single particle KW - Brightness KW - NIR KW - Mechanism KW - Single enhancement KW - SWIR KW - Method PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-537193 DO - https://doi.org/10.1002/adom.202101285. SN - 2195-1071 VL - 9 IS - 24 SP - 2101285 PB - Wiley-VCH-GmbH AN - OPUS4-53719 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute A1 - Wegner, Karl David A1 - Kalot, G. A1 - Busser, B. A1 - Pliquett, J. A1 - Köster, U. A1 - Koll, J. C. A1 - Denat, F. A1 - Bodio, E. A1 - Goze, C. A1 - Sacey, L. T1 - NIR aza-BODIPY: a new vector for boron neutron capture therapy (BNCT) N2 - Boron neutron capture therapy (BNCT) relies on the activation of 10B by thermal neutrons, which results in small highly energetic particle emission inducing cancer cells damage. However, in order to overcome the limits of the currently used BNCT agents, it is necessary to design new systems, which can specifically accumulate and deliver a sufficient amount of 10B in tumors. In this study, we designed a 10B-BSH-containing aza-BODIPY (aza-SWIR-BSH). It enabled the efficient vectorization of clinically used 10B-BSH to the tumor, resulting in higher therapeutic activity than the 10B-BSH alone. T2 - EMIM 2021 CY - Göttingen, Germany DA - 24.08.2021 KW - Flourescence KW - Optical probe KW - Dye KW - Photophysics KW - Quantum yield KW - Mechanism KW - NIR KW - SWIR KW - Imaging KW - Method KW - Quality assurance KW - BODIPY KW - Boron Neutron Capture Therapy (BNCT) KW - Medicine KW - Life sciences PY - 2021 AN - OPUS4-53731 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Daly, H.C A1 - Matikonda, S.S A1 - Steffens, H.C A1 - Rühle, Bastian A1 - Resch-Genger, Ute A1 - Ivanic, J. A1 - Schermann, M.J T1 - Daly_Photochem Photobiol 2021_Ketone Incorporation Extends the Emission Properties of the Xanthene Scaffold N2 - Imaging in the shortwave-infrared region (SWIR, λ = 1000–2500 nm) has the potential to enable deep tissue imaging with high resolution. Critical to the development of these Methods is the identification of low molecular weight, biologically compatible fluorescent probes that emit beyond 1000 nm. Exchanging the bridging oxygen atom on the xanthene scaffold (C10’ position) with electron withdrawing groups has been shown to lead to significant redshifts in absorbance and emission. Guided by quantum chemistry computational modeling studies, we investigated the installation of a Ketone bridge at the C10’ position. This simple modification extends the absorbance maxima to 860 nm and the emission beyond 1000 nm, albeit with reduced photon output. Overall, These studies demonstrate that broadly applied xanthene dyes can be extended into the SWIR range. KW - Flourescence KW - Optical probe KW - Dye KW - Photophysics KW - Quantum yield KW - Mechanism KW - NIR KW - SWIR KW - Imaging KW - Reliability KW - Method KW - Quality assurance PY - 2021 DO - https://doi.org/10.1111/php.13544 SN - 1751-1097 VL - 98 IS - 2 SP - 325 EP - 333 PB - Wiley Online Library AN - OPUS4-54080 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute A1 - Würth, Christian A1 - Frenzel, Florian A1 - Weigert, Florian A1 - Andresen, Elina A1 - Grauel, Bettina A1 - Wegner, Karl David T1 - Semiconductor (SCNC) & Upconversion Nanocrystals (UCNC) – Optical Properties, Applications & Challenges N2 - Inorganic nanocrystals with linear and nonlinear luminescence in the ultraviolet, visible, near infrared and shortwave infrared like semiconductor quantum dots and spectrally shifting lanthanide-based nanophosphors have meanwhile found applications in the life and material sciences ranging from optical reporters for bioimaging and sensing over security barcodes to solid state lighting and photovoltaics. These nanomaterials commonly have increasingly sophisticated core/shell particle architectures with shells of different chemical composition and thickness to minimize radiationless deactivation at the particle surface that is usually the main energy loss mechanism [1]. For lanthanide-based spectral shifters, particularly for very small nanoparticles, also surface coatings are needed which protect near-surface lanthanide ions from luminescence quenching by high energy vibrators like O-H groups and prevent the disintegration of these nanoparticles under high dilution conditions. [2,3,4]. The identification of optimum particle structures requires quantitative spectroscopic studies focusing on the key performance parameter photoluminescence quantum yield [5,6], ideally flanked by single particle studies to assess spectroscopic inhomogeneities on a particle-to-particle level for typical preparation methods [7], Moreover, in the case of upconversion nanoparticles with a multi-photonic and hence, excitation power density (P)-dependent luminescence, quantitative luminescence studies over a broad P range are required to identify particle architectures that are best suited for applications in fluorescence assays up to fluorescence microscopy. Here, we present methods to quantify the photoluminescence of these different types of emitters in the vis/NIR/SWIR and as function of Pand demonstrate the importance of such measurements for a profound mechanistic understanding of the nonradiative deactivation pathways in semiconductor and upconversion nanocrystals of different size and particle architecture in different environments. T2 - 27th Annual Meeting of the Slovenian Chemical Society CY - Portoroz-Portorose, Slovenia DA - 21.09.2021 KW - Nano KW - Nanomaterial KW - Upconversion nanoparticle KW - Lanthanide KW - Photoluminescence KW - Quantum yield KW - Photophysics KW - Lifetime KW - Surface chemistry KW - Single particle KW - Brightness KW - NIR KW - Synthesis KW - Semiconductur KW - Quantum dot KW - Nanocrystal KW - SWIR PY - 2021 AN - OPUS4-53723 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauli, Jutta A1 - Würth, Christian A1 - Güttler, Arne A1 - Resch-Genger, Ute T1 - Reliable Determination of the Signal-Relevant Spectroscopic Key Characteristics of Luminescent Reporters and Optical Probes for Imaging in the vis/NIR/SWIR N2 - Introduction. Comparing different emitter classes and rationally designing the next generation of molecular and nanoscale probes for bioimaging applications require accurate and quantitative methods for the measurement of the key parameter photoluminescence quantum yield f.1 f equals the number of emitted per number of absorbed photons. This is particularly relevant for increasingly used fluorescence imaging in the short wave-infrared region (SWIR) ≥ 900 nm providing deeper penetration depths, a better image resolution, and an improved signal-to-noise or tumor-to-background ratio.2, 3 However, spectroscopic measurements in the SWIR are more challenging and require specific calibrations and standards. T2 - EMIM 2021 CY - Göttingen, Germany DA - 24.08.2021 KW - Fluorescence KW - Optical probe KW - Dye KW - Photophysics KW - Quantum yield KW - Mechanism KW - NIR KW - SWIR KW - Imaging KW - Reference material KW - Reliability KW - Nano KW - Particle KW - Method KW - Quality assurance PY - 2021 AN - OPUS4-53233 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yu, Z. A1 - Musnier, B. A1 - Wegner, Karl David A1 - Henry, M. A1 - Chovelon, B. A1 - Desroches-Castan, A. A1 - Fertin, A. A1 - Resch-Genger, Ute A1 - Bailly, S. A1 - Coll, J.-L. A1 - Usson, Y, A1 - Josserand, V. A1 - Le Gúevel, X. T1 - High-Resolution Shortwave Infrared Imaging of Vascular Disorders Using Gold Nanoclusters N2 - We synthesized a generation of water-soluble, atomically precise gold nanoclusters (Au NCs) with anisotropic Surface containing a short dithiol pegylated chain (AuMHA/TDT). The AuMHA/TDT exhibit a high brightness (QY ∼ 6%) in the shortwave infrared (SWIR) spectrum with a detection above 1250 nm. Furthermore, they show an extended half-life in blood (t1/2ß = 19.54 ± 0.05 h) and a very weak accumulation in organs. We also developed a non-invasive, whole-body vascular imaging system in the SWIR window with high-resolution, benefiting from a series of Monte Carlo image processing. The imaging process enabled to improve contrast by 1 order of magnitude and enhance the spatial Resolution by 59%. After systemic administration of these nanoprobes in mice, we can quantify vessel complexity in depth (>4 mm), allowing to detect very subtle vascular disorders non-invasively in bone morphogenetic protein 9 (Bmp9)-deficient mice. The combination of these anisotropic surface charged Au NCs plus an improved SWIR imaging device allows a precise mapping at high-resolution and an in depth understanding of the organization of the vascular network in live animals. KW - Nanoparticle KW - Nanosensor KW - Fluorescence KW - Metal cluster KW - NIR KW - SWIR KW - Photophysics KW - Ligand KW - Size KW - Surface chemistry KW - Quantum yield KW - Mechanism KW - Lifetime KW - Decay kinetics PY - 2020 DO - https://doi.org/10.1021/acsnano.0c01174 VL - 14 IS - 4 SP - 4973 EP - 4981 PB - ACS Publication AN - OPUS4-50671 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Godard, A. A1 - Kalot, G. A1 - Pliquett, J. A1 - Busser, B. A1 - Le Guével, X. A1 - Wegner, Karl David A1 - Resch-Genger, Ute A1 - Russelin, Y. A1 - Coll, J.-L. A1 - Denat, F. A1 - Bodio, E. A1 - Goze, C. A1 - Sancey, L. T1 - Water-Soluble Aza-BODIPYs: Biocompatible Organic Dyes for High Contrast In Vivo NIR-II Imaging N2 - A simple NIR-II emitting water-soluble system has been developed and applied in vitro and in vivo. In vitro, the fluorophore quickly accumulated in 2D and 3D cell cultures and rapidly reached the tumor in rodents, showing high NIR-II contrast for up to 1 week. This very efficient probe possesses all the qualities necessary for translation to the clinic as well as for the development of NIR-II emitting materials. KW - Aza-BODIPY KW - NIR-II Imaging KW - In vivo imaging KW - organic dyes KW - SWIR KW - Cancer KW - Fluorescence PY - 2020 DO - https://doi.org/10.1021/acs.bioconjchem.0c00175 VL - 31 IS - 4 SP - 1088 EP - 1092 PB - ACS Publications AN - OPUS4-50695 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -