A5042353808- Advanced Fluorescence Microscopy Techniques
- Quantum Dots Synthesis And Properties
- Photonic and Optical Devices
- Molecular Junctions and Nanostructures
- Advanced Electron Microscopy Techniques and Applications
- Plasmonic and Surface Plasmon Research
- Gold and Silver Nanoparticles Synthesis and Applications
- Silicon Nanostructures and Photoluminescence
- Near-Field Optical Microscopy
- Mechanical and Optical Resonators
- Carbon and Quantum Dots Applications
- Nanowire Synthesis and Applications
- Chalcogenide Semiconductor Thin Films
- Photonic Crystals and Applications
- Cellular Mechanics and Interactions
- Force Microscopy Techniques and Applications
- Advanced X-ray and CT Imaging
- HER2/EGFR in Cancer Research
- Ion-surface interactions and analysis
- Advanced biosensing and bioanalysis techniques
- Medical Imaging Techniques and Applications
- Porphyrin and Phthalocyanine Chemistry
- Luminescence and Fluorescent Materials
- Lipid Membrane Structure and Behavior
- Integrated Circuits and Semiconductor Failure Analysis
University of Göttingen
2016-2025
Czech Academy of Sciences, Institute of Physics
2015-2020
University of Tübingen
2009-2013
KTH Royal Institute of Technology
2012
Helmholtz Institute Jena
2009-2010
Max Planck Institute for Astronomy
2009-2010
St Petersburg University
2010
Institute of Physics
2010
Inorganic carbon nanomaterials, also called nanodots, exhibit a strong photoluminescence with unusual properties and, thus, have been the focus of intense research. Nonetheless, origin their is still unclear and subject scientific debates. Here, we present single particle comprehensive study nanodot photoluminescence, which combines emission lifetime spectroscopy, defocused dipole imaging, azimuthally polarized excitation scanning, nanocavity-based quantum yield measurements, high resolution...
Success in super-resolution imaging relies on a proper choice of fluorescent probes. Here, we suggest novel easily produced and biocompatible nanoparticles-carbon nanodots-for optical fluctuation bioimaging (SOFI). The particles revealed an intrinsic dual-color fluorescence, which corresponds to two subpopulations different electric charges. neutral nanoparticles localize cellular nuclei suggesting their potential use as inexpensive, nucleus-specific label. single particle study that the...
Mutations within the epidermal growth factor receptor (EGFR/erbB1/Her1) are often associated with tumorigenesis. In particular, a number of EGFR mutants that demonstrate ligand-independent signaling common in non–small cell lung cancer (NSCLC), including kinase domain mutations L858R (also called L834R) and exon 19 deletions (e.g., ΔL747-P753insS), which collectively make up nearly 90% NSCLC. The molecular mechanisms by these confer constitutive activity remain unresolved. Using multiple...
Abstract Imaging of complex (biological) samples in the near-infrared (NIR) is beneficial due to reduced light scattering, absorption, phototoxicity, and autofluorescence. However, there are few NIR fluorescent materials known suitable for biomedical applications. Here we exfoliate layered pigment CaCuSi 4 O 10 (Egyptian Blue, EB) via ball milling facile tip sonication into nanosheets (EB-NS). The size EB-NS can be tailored diameters <20 nm heights down 1 nm. fluoresce at 910 fluorescence...
We present experimental and theoretical results on changing the fluorescence emission spectrum of a single molecule by embedding it within tunable planar microcavity with subwavelength spacing. The cavity length is changed nanometer precision using piezoelectric actuator. By varying its length, local mode structure electromagnetic field together radiative coupling emitting to field. Because are both frequency dependent, this leads renormalization molecule. develop model for these spectral...
Abstract We present a new concept for measuring distance values of single molecules from surface with nanometer accuracy using the energy transfer excited molecule to plasmons metal film. measure fluorescence lifetime individual dye deposited on dielectric spacer as function thickness. By our theoretical model, we convert into axial molecules. Similar Förster resonance (FRET), this allows emitters be localized accuracy, but in contrast FRET range at which efficient takes place is an order...
The role of quantum confinement (QC) and surface-related defect centers (DCs) on the photoluminescence (PL) individual silicon nanocrystals (Si NCs) is investigated using confocal microscopy with radially azimuthally polarized laser beams. It shown that multiple-peak PL spectra single Si NCs revealing SiO${}_{2}$ phonon side bands are associated a linear transition dipole moment (TDM) short lifetime 4 ns, indicating originates from centers. In new study applied to free-standing obtained by...
Using a tunable optical microresonator with subwavelength spacing, we demonstrate controlled modulation of the radiative transition rate single molecule, which is measured by monitoring its fluorescence lifetime. Variation cavity length changes local mode structure electromagnetic field, modifies coupling an emitting molecule to that field. By comparing experimental data theoretical model, extract both pure as well quantum yield individual molecules. We observe broad scattering values from...
The biological process of the epithelial-to-mesenchymal transition (EMT) allows epithelial cells to enhance their migratory and invasive behavior plays a key role in embryogenesis, fibrosis, wound healing, metastasis. Among multiple biochemical changes from an mesenchymal phenotype, alteration cellular dynamics cell–cell as well cell–substrate contacts is crucial. To determine these variations over whole time scale EMT, we measure distance NMuMG during EMT using our newly established...
We present a new method for determining absolute values of quantum yield luminescent emitters, which is based on the modification radiative transition emitters within tunable metallic nanocavity. The presented easy to set up and works without any calibration. It will thus be useful all applications where calibration-free measurements luminescence yields are needed. Moreover, it requires only minute amount low-concentration fluorophore solution. give detailed description theory data...
Single-molecule localization based super-resolution microscopy has revolutionized optical and routinely allows for resolving structural details down to a few nanometers. However, there exists rather large discrepancy between lateral axial accuracy, the latter typically three five times worse than former. Here, we use single-molecule metal-induced energy transfer (smMIET) localize single molecules along axis, measure their distance with an accuracy of 5 nm. smMIET relies only on fluorescence...
The nuclear envelope, comprising the inner and outer membrane, separates nucleus from cytoplasm plays a key role in cellular functions. Nuclear pore complexes (NPCs), which are embedded control transport of macromolecules between two compartments. Here, using dual-color metal-induced energy transfer (MIET), we determine axial distance Lap2β Nup358 as markers for membrane cytoplasmic side NPC, respectively. Using MIET imaging, reconstruct 3D profile envelope over whole basal area, with an...
This study focuses on the mechanism of fluorescence blinking single carbon nanodots, which is one their key but less understood properties. The results our single-particle show that nanodots has remarkable similarities with semiconductor quantum dots. In particular, temporal behavior nanodot follows a power law both at room and cryogenic temperatures. Our experimental data suggest static quenching via Dexter-type electron transfer between surface groups nanoparticle plays major role in...
Over the past two decades, super-resolution microscopy has seen a tremendous development in speed and resolution, but for most of its methods, there exists remarkable gap between lateral axial which is by factor 2 to 3 worse. One recently developed method close this metal-induced energy transfer (MIET) imaging, achieves an resolution down nanometers. It exploits distance-dependent quenching fluorescence when fluorescent molecule brought metal surface. In present manuscript, we combine...
We study the dimensionality of excitation transition dipole moment for single CdSe/ZnS core−shell nanocrystals using azimuthally and radially polarized laser modes. The comparison measured simulated nanocrystal patterns shows that quantum dots possess a spherically degenerated dipole. show distribution is same all individual nanocrystals, disregarding difference in core size irrespective variations local environment. In contrast to emission moment, which oriented one plane, possesses an...
Tautomerism process of single fluorescent molecules was studied by means confocal microscopy in combination with azimuthally or radially polarized laser beams. During a tautomerism the transition dipole moment (TDM) molecule changes its orientation which can be visualized fluorescence excitation image molecule. We present experimental and theoretical studies two porphyrazine-type one type porphyrin molecule: symmetrically substituted metal-free phthalocyanine porphyrin, nonsymmetrically...
Our paper presents the first theoretical and experimental study using single-molecule Metal-Induced Energy Transfer (smMIET) for localizing single fluorescent molecules in three dimensions. describes resonant energy transfer from excited state of a emitter to surface plasmons metal nanostructure. This is strongly distance-dependent can be used localize an along one dimension. We have past emitters with nanometer accuracy optical axis microscope. The combination smMIET localization based...
Metal-induced energy transfer (MIET) imaging is an easy-to-implement super-resolution modality that achieves nanometer resolution along the optical axis of a microscope. Although its capability in numerous biological and biophysical studies has been demonstrated, implementation for live-cell with fluorescent proteins still lacking. Here, we present applicability capabilities diverse cell types (adult human stem cells, osteo-sarcoma Dictyostelium discoideum cells), various (GFP, mScarlet,...
Electric charges play a fundamental role in shaping the structure, function, and interactions of biomolecules, yet precisely measuring these at single-molecule level remains significant technical challenge. Here, we introduce novel experimental methodology that utilizes plasmonic nanocavities to quantify molecular electric solution with high sensitivity. Our approach exploits an externally applied field induce spatial redistribution charged molecules confined within planar metallic...