Ingenieurwissenschaften und zugeordnete Tätigkeiten
Filtern
Erscheinungsjahr
Dokumenttyp
- Zeitschriftenartikel (124)
- Vortrag (62)
- Beitrag zu einem Tagungsband (5)
- Posterpräsentation (3)
- Sonstiges (2)
- Buchkapitel (1)
- Corrigendum (1)
Schlagworte
- Quantum yield (98)
- Fluorescence (89)
- Nano (55)
- NIR (54)
- Lifetime (53)
- Dye (49)
- Nanoparticle (47)
- Photophysics (45)
- Quality assurance (43)
- Sensor (41)
- Lanthanide (37)
- Photoluminescence (36)
- Upconversion (35)
- Particle (34)
- Integrating sphere spectroscopy (31)
- Surface chemistry (30)
- Method (27)
- Nanomaterial (26)
- Mechanism (21)
- IR (19)
- SWIR (19)
- Quantification (18)
- Synthesis (18)
- Upconversion nanoparticle (18)
- Reference material (17)
- Energy transfer (16)
- Brightness (14)
- Luminescence (13)
- Quantum dot (13)
- Semiconductor quantum dot (13)
- Absolute fluorometry (12)
- Calibration (12)
- Quantitative spectroscopy (12)
- Single particle (11)
- Imaging (10)
- Optical spectroscopy (10)
- Size (10)
- Aggregation (9)
- Ligand (9)
- Multiplexing (9)
- Standard (9)
- Uncertainty (9)
- Assay (8)
- Fluorescence standard (8)
- Nanocrystal (8)
- Optical probe (8)
- Polymer (8)
- Semiconductor (8)
- Surface analysis (7)
- Temperature (7)
- Absolute fluorescence quantum yield (6)
- Application (6)
- Coating (6)
- Crystal (6)
- Deactivation pathways (6)
- Excitation power density (6)
- Flourescence (6)
- Microscopy (6)
- Nanoparticles (6)
- Optical assay (6)
- Quantum dots (6)
- Surface group analysis (6)
- Bead (5)
- Cell (5)
- Life sciences (5)
- Measurement uncertainty (5)
- Modeling (5)
- Signal enhancement (5)
- Silica (5)
- Single particle spectroscopy (5)
- Stability (5)
- Switch (5)
- Upconverting nanoparticles (5)
- BODIPY (4)
- Electrochemistry (4)
- Environment (4)
- FRET (4)
- Fluorescence decay kinetics (4)
- Instrument calibration (4)
- PDT (4)
- Probe (4)
- Rare earth nanoparticles (4)
- SAXS (4)
- Standardization (4)
- Traceability (4)
- Upconversion nanocrystal (4)
- pH (4)
- AIE (3)
- AIS (3)
- Absolute flourometry (3)
- Active fibers (3)
- Aggregation-induced emission (3)
- Aging (3)
- Antibody (3)
- Barcoding (3)
- Bioimaging (3)
- Certification (3)
- Cleavable probe (3)
- Conductometry (3)
- Cr(III) (3)
- Encoding (3)
- Enhancement (3)
- Flow cytometry (3)
- Fluorescence quantum yield (3)
- Fluoride (3)
- ICP-OES (3)
- Interlaboratory comparison (3)
- Label (3)
- Linearity (3)
- Method development (3)
- Method validation (3)
- Modelling (3)
- NMR (3)
- Nano particle (3)
- Nanomaterials (3)
- PEG (3)
- Polarity (3)
- Power density dependence (3)
- Reference data (3)
- Reference product (3)
- Reporter (3)
- Sensitization (3)
- Sensors (3)
- Shell (3)
- Solid state emission (3)
- Surface (3)
- TEM (3)
- XPS (3)
- Yb(III) complex (3)
- Absolute fluoreometry (2)
- Absolute fluorescence (2)
- Aggregation induced emission (2)
- Analytics (2)
- Bead-based assay (2)
- Cancer (2)
- Cell studies (2)
- Characterization (2)
- Comparison (2)
- Conjugate (2)
- Contrast agent (2)
- Copolymer (2)
- Cyanine (2)
- DNA (2)
- Electron microscopy (2)
- Enhancement strategy (2)
- Excitation (2)
- FLIM (2)
- Fluorescent glasses (2)
- Functional group analysis (2)
- Gold (2)
- Ho(III) (2)
- Hydration (2)
- Integrating sphere (2)
- Iron oxide (2)
- Liftetime (2)
- Ligand analysis (2)
- Limit of detection (2)
- Llifetime (2)
- Mass spectrometry (2)
- Metal cluster (2)
- Method comparison (2)
- Microfluidics (2)
- Microparticle (2)
- Monitoring (2)
- Monomer (2)
- Nanosensor (2)
- Nile Red (2)
- Particle architecture (2)
- Performance validation (2)
- Phosphor (2)
- Photonic crystal (2)
- Polymer particle (2)
- Power density (2)
- Protein (2)
- Quantum Yield (2)
- Quantum rod (2)
- Quantum yields (2)
- Quenching (2)
- Reliability (2)
- Safety (2)
- Semiconducor nanocrystals (2)
- Semiconductor nanocrystal (2)
- Semiconductor nanocrystals (2)
- Sensing (2)
- Sensor molecules (2)
- Simulation (2)
- Singlet oxygen (2)
- Spectroscopy (2)
- Surface group quantification (2)
- Surface modification (2)
- Sythesis (2)
- Ternary quantum dots (2)
- Theory (2)
- Thiol ligand (2)
- Triplet-triplet annihilation (2)
- Upconverion (2)
- Upconversion nanoparticles (2)
- Yb(III) (2)
- fluorescence (2)
- pH probe (2)
- 150th anniversary (1)
- A4F (1)
- ABC (1)
- AIS QD (1)
- Ab initio calculation (1)
- Absolute (1)
- Absolute flourescence (1)
- Absolute measurement (1)
- Absorption (1)
- Activatable probe (1)
- Adsorption (1)
- Advanced Materials (1)
- Advanced material (1)
- Advanced materials (1)
- Advanced nanomaterials (1)
- Aldrithiol (1)
- Amplification (1)
- Analysis (1)
- Analytical sciences (1)
- Analytical services (1)
- Artificial weathering (1)
- Automated synthesis (1)
- Automation (1)
- Aza-BODIPY (1)
- BAM (1)
- Bacteria (1)
- Bioconjugate (1)
- Biofilm (1)
- Biomarker (1)
- Biophotonics (1)
- Biosensing (1)
- Boron Neutron Capture Therapy (BNCT) (1)
- Brithtness (1)
- Bundesanstalt für Materialforschung und -prüfung (1)
- C-dot (1)
- COSMO (1)
- CRP (1)
- Calibrated fluorescence measurements (1)
- Capillary electrophoresis (1)
- Carbon (1)
- Carbon dot (1)
- Carboxyl group (1)
- Catalogue of services (1)
- Catch and release assay (1)
- CdSe (1)
- Cellular uptake (1)
- Cement (1)
- Cement hydration (1)
- Certified reference material (1)
- Charge transfer (1)
- Chiral (1)
- Circular dichroism (1)
- Cleavable linker (1)
- Cleavable probes (1)
- Cluster (1)
- Collection (1)
- Color (1)
- Color tuning (1)
- Complex (1)
- Conductor-like screening model (1)
- Converter marterial (1)
- Converter material (1)
- Core shell structure (1)
- Core-shell architecture (1)
- Core-shell nanoparticles (1)
- Core/shell particle (1)
- Corrosion (1)
- Cr complex (1)
- Critical micelle concentration (CMC) (1)
- Crosslinking (1)
- Cubical shape (1)
- Cysteine (1)
- DNA origami (1)
- DPA (1)
- Decay kinetics (1)
- Decay time (1)
- Degradation (1)
- Density functional theory (DFT) (1)
- Design of experiment (1)
- Dipole moment (1)
- Dodecanethiol (1)
- Dual emission (1)
- Dual sensing (1)
- Dye labeling (1)
- Dyes (1)
- EC4SafeNano (1)
- Editorial (1)
- Electrochemical titration (1)
- Ellman (1)
- Emission enhancement (1)
- Emission standards (1)
- Er(III) (1)
- European Centre (1)
- Excitation energy dependence (1)
- Excitation power density dependence (1)
- Excitation spectra (1)
- Exciton (1)
- Field sensor (1)
- Film (1)
- Fluoranthene (1)
- Fluorescence intensity ratio (1)
- Fluorescence lifetime (1)
- Fluorescence microscopy (1)
- Fluorescence probe (1)
- Fluorescence spectroscopy (1)
- Fluorescent label (1)
- Fluorescent probe (1)
- Fluorometry (1)
- Fluorophore (1)
- Fully aromatic frameworks (1)
- Functional group quantification (1)
- Funtional Groups (1)
- Giant carbon dot (1)
- Glass (1)
- Gold nanocluster (1)
- Gold nanoclusters (1)
- Green synthesis (1)
- Heory (1)
- Homogeneity (1)
- IR fluorescence (1)
- IR spectroscopy (1)
- Immunoassay (1)
- In vivo imaging (1)
- Infrastructure (1)
- Instrument qualification (1)
- Integrating sphare spectroscopy (1)
- Integrating sphere spectroscopy, (1)
- Interlaboratory (1)
- Interlabority comparison (1)
- Jahrestag (1)
- K+ doped (1)
- LT-FCM (1)
- Lanthanide-doped nayf-4 (1)
- Lanthanides (1)
- Legionella (1)
- LiYF4 (1)
- Lifetime analysis (1)
- Ligand exchange (1)
- Ligand quantification (1)
- Ligands (1)
- Light harvesting (1)
- Luorescence (1)
- MIC (1)
- MOF (1)
- MS (1)
- Magic-sized cluster (1)
- Magnetic (1)
- Material sciences (1)
- Materials (1)
- Medicine (1)
- Merocyanine (1)
- Metal (1)
- Metasurface (1)
- Method evaluation (1)
- Methods (1)
- Methos comparision (1)
- Micelle (1)
- Microbiology (1)
- Microorganism (1)
- Miniaturization (1)
- Moisture (1)
- Molecular beacon (1)
- Molecular diagnostics (1)
- NIR dyes (1)
- NIR-II Imaging (1)
- NIR-II fluorescence (1)
- NIRII (1)
- NMR spectroscopy (1)
- Nanaoparticle (1)
- Nano CRM (1)
- Nano-safety (1)
- Nanocrystals (1)
- Nanomaterial design (1)
- Nanopartikel (1)
- Nanophosphor (1)
- Nanoplatelet (1)
- Nanosafety (Safe-by-design) (1)
- Nanoscale luminescent reporters (1)
- Nanotoxicity (1)
- Nd excitation (1)
- Near infrared (1)
- Near-infrared light (1)
- Nicht lineare Prozesse (1)
- Nnano particle (1)
- Non lienear processes (1)
- Non-thermally coupled levels (1)
- Nonlinear (1)
- One-pot synthesis (1)
- Optical Spectroscopy (1)
- Optical detection (1)
- Optical probes (1)
- Optical spectroscopie (1)
- Optical temperature sensing (1)
- Organic–inorganic nanostructures (1)
- Origami (1)
- Oxygen (1)
- Oxygen sensitive (1)
- PEG ligands (1)
- PET (1)
- PH (1)
- Particle Synthesis (1)
- Particle sensors (1)
- Particle synthesis (1)
- Particle, imaging (1)
- Pd(II) (1)
- Perovskite (1)
- Perovskites (1)
- Ph (1)
- Phosphinine (1)
- Photo physics (1)
- Photocatalytic activity (1)
- Photoluminescence quantum yield (1)
- Photophysic (1)
- Photosensitizer (1)
- Pitfalls (1)
- Pollutant (1)
- Poloxazolines (1)
- Polycarboxylate ether (1)
- Polymer particles (1)
- Polymers (1)
- Polyurethane (1)
- Porphyrin (1)
- Pphotophysics (1)
- Production (1)
- Protein corona (1)
- Pt(II) (1)
- QNMR (1)
- Qantum yield (1)
- Quality assurcance (1)
- Quantenausbeute (1)
- Quantitative Analysis (1)
- Quantum chemistry (1)
- Quantum do (1)
- Quantum yield standard (1)
- Quinones (1)
- Ratiometric (1)
- Ratiometric sensing (1)
- Redox (1)
- Reference maerial (1)
- Reference materials (1)
- Reference nanoparticles (1)
- Reflection spectroscopy (1)
- Release (1)
- Renewable energy (1)
- Reproducibility (1)
- Reverse microemulsion (1)
- Rheology (1)
- Risk assessment (1)
- Rreference material (1)
- SWIR photoluminescence (1)
- Safe-by-Design (1)
- Scattering (1)
- Self-assembly (1)
- Semiconductur (1)
- Shape (1)
- Signal amplification (1)
- Silanization (1)
- Silica and Polystyrene Particles (1)
- Silica and polystyrene nanoparticles (1)
- Silica coating (1)
- Single emitter (1)
- Single enhancement (1)
- Single molecule (1)
- Small-angle scattering (1)
- Solar cell (1)
- Solar concentrator (1)
- Solar energy (1)
- Solid (1)
- Special issue (1)
- Spectral correction (1)
- Spectroscopy / Instrumentation (1)
- Spectroscopy / Theory (1)
- SrF2 (1)
- Standards (1)
- Stepwise growth (1)
- Surface Chemistry (1)
- Surface coating (1)
- Surface group (1)
- Surface groups (1)
- Surface ligand (1)
- Suzuki-Miyaura coupling (1)
- Syntheseis (1)
- Tag (1)
- Therapy (1)
- Thermal coupling energy level (1)
- Thermally coupled levels (1)
- Thick shells (1)
- Thickness (1)
- Thiol (1)
- Thiol assay (1)
- Thiols (1)
- Time-gated emission (1)
- Time-resolved flow cytometry (1)
- Toxicity (1)
- Triggered (1)
- UV Vis (1)
- UV/Vis and emission spectroscopy (1)
- Upconversion luminescence (1)
- Upconversion nanocrystals (1)
- Upconverstion (1)
- VAMAS (1)
- X-ray (1)
- X-ray diffractometry (XRD) (1)
- X-ray spectroscopy (1)
- Zinc(II) complexes (1)
- ZnSe (1)
- antibody (1)
- bacteria (1)
- bacteria detection (1)
- biotechnological (1)
- calibration (1)
- carrier system (1)
- dye (1)
- flow cytometry (1)
- fluorescence microscopy (1)
- fluorescence standards (1)
- fluorescent reporter (1)
- immunoseparation (1)
- laponite (1)
- lifetime (1)
- magnetic nanoparticle (1)
- method (1)
- nanoclay (1)
- nanocrystals (1)
- nanoparticle (1)
- organic dye (1)
- organic dyes (1)
- particle (1)
- pharmaceutical (1)
- photoluminescence (1)
- photoluminescence quantum yield (1)
- photophysics (1)
- photovoltaics (1)
- quality assurcance (1)
- quantum dot (1)
- quantum yield (1)
- screening (1)
- screening tes (1)
- solar cell (1)
- surface group analysis (1)
- synthesis (1)
Organisationseinheit der BAM
- 1 Analytische Chemie; Referenzmaterialien (151)
- 1.2 Biophotonik (151)
- 6 Materialchemie (14)
- 6.1 Oberflächen- und Dünnschichtanalyse (11)
- 6.3 Strukturanalytik (4)
- 1.0 Abteilungsleitung und andere (3)
- 1.7 Organische Spuren- und Lebensmittelanalytik (3)
- 5 Werkstofftechnik (3)
- 7 Bauwerkssicherheit (3)
- 4 Material und Umwelt (2)
Paper des Monats
- ja (5)
Eingeladener Vortrag
- nein (62)
Photoluminescence techniques are amongst the most widely used tools in the material and life sciences, with new and exciting applications continuously emerging, due to their many advantages like comparative ease of use, unique sensitivity, non-invasive character, and potential for multiplexing, remote sensing, and miniaturization. Drawbacks are , however, signals, that contain unwanted wavelength- and polarization contributions from instrument-dependent effects, which are time-dependent due to the aging of instrument components, and difficulties to measure absolute fluorescence intensities. Thus, there is a considerable need for standards for intensity, spectral, and temporal fluorescence quantities to meet the increasing need for instrument performance validation and global trends to harmonize physicochemical measurements. In this respect, instrument calibration strategies together with different types of fluorescence standards are presented as well as design concepts for robust, easy-to-use, and format-adaptable fluorescence standards useable for the determination of different fluorescence parameters and a broad variety of fluorescence techniques.
There is an increasing interest in optical reporters like semiconductor quantum dots and upconversion nanocrystals with emission > 800 nm for bioanalysis, medical diagnostics, and safety barcodes. Prerequisites for the comparison of material performance, the mechanistic understanding of nonradiative decay channels, and the rational design of new nanomaterials with improved properties are reliable fluorescence measurements and validated methods for the assessment of their surface chemistry. The latter is of special relevance for nanocrystalline emitters, where surface states and the accessibility of emissive states by quenchers largely control accomplishable photoluminescence quantum yields and hence, signal sizes and detection sensitivities from the reporter side. Here, we present the design of integrating sphere setups for the excitation power density-dependent absolute measurement of emission spectra and photoluminescence quantum yields in the wavelength region of 350 to 1600 nm and results from spectroscopic studies of semiconductor quantum dots and upconversion nanocrystals of different size and surface chemistries in various environments. Subsequently, examples for simple approaches to surface group and ligand analysis are presented.
Here, we present an overview of the research activities of division Biophotonics concerning the design and (bio)analytical application of molecular and nanoscale functional chromophores for e.g., biomarker analysis including methods for the reliable determination of their application relevant properties. This includes the absolute determination of their brightness and photoluminescemce quantum yield, determining the signal size from the material side, as well as the development of fluorescence standards for such measurements and instrument calibration strategies, thereby providing important prerequisites for the comparison of material performance, the mechanistic understanding of nonradiative decay channels, and the rational design of new optical reporters. Moreover, for particle-based systems, ranging from nm-sized semiconductor quantum dots to m-sized polymeric and silica beads, simple optical methods and assays for the assessment of their surface chemistry are presented, which enable the quantification of the number of total and derivatizable surface functionalities, ligands per particle and particle-bound biomolecules. In addition, validation concepts for such methods are introduced utilizing method comparisons, multimodal and cleavable probes.
Chemical admixtures like superplasticisers or stabilising agents are of ever increasing importance for modern concrete technology. They liberate the workability of concrete from its dependency on water content, and thus, open the gate towards innovative and future oriented concrete technologies such as selfcompacting concrete. Meanwhile admixtures have become common practice in concrete technology, but the understanding of these highly complex polymers in the entire concrete system lags far behind their application. Due to its complex time-dependent, multi-phase and multi-scale behaviour, flowable concrete systems are highly complicated and cannot be described comprehensively by simple models. It is therefore extremely challenging to identify the relevant parameters that predominantly control flow phenomena on different size scales, since these may occur on any scale between the nano scale (e.g. superplasticizer adsorption) and macro scale (e.g. grading of the aggregates). The present study discusses fundamental mechanisms at the interface between particle or hydrate surfaces and the fluid phase at a very early stage of concrete formation, and links these effects to macroscopic flow phenomena. Methods are discussed that appear promising interdisciplinary tools for enhancement of the understanding of the relevant interactions that are responsible for the macroscopic flow of flowable concrete.
Nanoclays like laponites, which are commercially avaible in large quantities for a very moderate price, provide a facile solubilization strategy for hydrophobic dyes without the need for chemical functionalization and can act as a carrier for a high number of dye molecules. This does not require reactive dyes, amplifies fluorescence signals from individual emitters due to the high number of dyes molecules per laponite disk, and renders hydrophobic emitters applicable in aqueous environments. Aiming at the rational design of bright dye-loaded nanoclays as a new class of fluorescent reporters for bioanalysis and material sciences and the identification of dye structure−property relationships, we screened a series of commercial fluorescent dyes, differing in dye class, charge, and character of the optical transitions involved, and studied the changes of their optical properties caused by clay adsorption at different dye loading concentrations. Upon the basis of our dye loading density-dependent absorption and fluorescence measurements with S2105 and Lumogen F Yellow 083, we could identify two promising dye−nanoclay hybrid materials that reveal high fluorescence quantum yields of the nanoclay-adsorbed dyes of at least 0.20 and low dye self-quenching even at high dye-loading densities of up to 50 dye molecules per laponite platelet.
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. Generally recognized drawbacks, however, are signals, that contain unwanted wavelength- and polarization contributions from instrument-dependent effects, which are also time-dependent due to aging of instrument-components, and difficulties to measure absolute fluorescence intensities, thus rendering the use of intensity standards mandatory for quantification.
Recent developments in fluorescence-based assays in clinical, pharmaceutical, biotechnological and other areas, in conjunction with the increasing need for instrument performance validation and global trends to harmonize measurements have boosted the demand for robust, easy-to-use, readily-available, reliable, and well documented fluorescence standards. This includes e.g. fluorescence standards for the consideration of instrument-specific spectral and intensity distortions of measured signals and instrument performance validation as well as fluorescence intensity standards for the quantification from measured intensities and for signal refencing, thereby accounting for excitation light-induced intensity fluctuations. Moreover, there is an ever increasing need for fluorescence quantum yield standards with well known and preferably certified quantum yields. Moreover, although already challenging for the UV/vis/NIR spectral region, there is an increasing interest particularly by the fluorescence imaging community to expand the waveelngth region applied from the NIR to measurements > 1000 nm. Presently, there are no fluorescence standards for this wavelength region available, rendering the control of instrument calibration in this wavelength region basically impossible.
In this respect, we present reliable and validated procedures for the calibration of fluorescence measuring devices from 300 nm to 1700 nm using different types of physical and chemical standards. Moreover, a new set of fluorescence quantum yield standards covering the UV/vis/NIR is been introduced that is currently under certification at BAM.
Enzyme-activatable optical probes are important for future advances in cancer imaging, but may easily suffer from low signal-to-background ratios unless not optimized. To address this shortcoming, numerous mechanisms to modulate the fluorescence signal have been explored.
We report herein newly synthesized probes based on selfimmolative linkers containing chiral J-aggregate-forming dyes.
Signal modulation by formation of chiral J-aggregates is yet unexplored in optical enzyme probe design. The comprehensive characterization of the probes by absorption, CD, fluorescence, and time-resolved fluorescence spectroscopy revealed dye−dye interactions not observed for the free dyes in solution as well as dye−protein interactions with the enzyme. This suggested
that J-aggregate formation is challenging to achieve with current probe design and that interactions of the dyes with the Enzyme may interfere with achieving high signal-to-background ratios. The detailed understanding of the interactions provided herein provides valuable guidelines for the future design of similar probes.
We present colloidally stable and highly luminescent ZnxCd1_xS:Mn/ZnS core–shell nanocrystals (NCs) synthesized via a simple non-injection one-pot, two-step synthetic route, which can be easily upscaled. A systematic variation of the reaction component, parameters and thickness of the ZnS shell yielded doped nanocrystals with a very high photoluminescence quantum yield (pl) of 70%, which is the highest value yet reported for these Mn-doped sulfide-semiconductor NCs. These materials can be synthesized with high reproducibility in large quantities of the same high quality, i.e., the same pl using accordingly optimized reaction conditions. The application of these zero-reabsorption high quality NCs in the light conversion layers, deposited on top of a commercial monocrystalline silicon (mono-Si) solar cell, led to a significant enhancement of the external quantum efficiency (EQE) of this device in the ultraviolet spectral region between 300 and 400 nm up to ca. 12%. EQE enhancement is reflected by an increase in the power conversion efficiency (PCE) by nearly 0.5 percentage points and approached the theoretical limit (0.6%) expected from down-shifting for this Si solar cell. The resulting PCE may result in a BoM (bill of materials) cost reduction of app. 3% for mono-Si photovoltaic modules. Such small but distinct improvements are expected to pave the road for an industrial application of doped semiconductor NCs as cost-effective light converters for silicon photovoltaic (PV) and other optoelectronic applications.