A5011433872- Spectroscopy and Quantum Chemical Studies
- Photoreceptor and optogenetics research
- Photochemistry and Electron Transfer Studies
- DNA and Nucleic Acid Chemistry
- Advanced X-ray Imaging Techniques
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced Electron Microscopy Techniques and Applications
- Laser-Matter Interactions and Applications
- Spectroscopy Techniques in Biomedical and Chemical Research
- Mass Spectrometry Techniques and Applications
- Microfluidic and Capillary Electrophoresis Applications
- Spectroscopy and Laser Applications
- Laser-induced spectroscopy and plasma
- Neuroscience and Neural Engineering
- Ion-surface interactions and analysis
- Advanced biosensing and bioanalysis techniques
- Heat Transfer and Boiling Studies
- Surface Modification and Superhydrophobicity
- Cholinesterase and Neurodegenerative Diseases
- Molecular Communication and Nanonetworks
- Atmospheric Ozone and Climate
- Advanced X-ray and CT Imaging
- Molecular Junctions and Nanostructures
- Advanced Optical Sensing Technologies
Max Planck Institute for the Structure and Dynamics of Matter
2014-2025
Extreme Light Infrastructure Beamlines
2020-2025
Universität Hamburg
2019-2025
University of Groningen
2025
Hamburg Centre for Ultrafast Imaging
2023
Czech Academy of Sciences, Institute of Physics
2019-2020
Max Planck Society
2015
We report the results of an extended time-resolved study DNA nucleobases in aqueous solutions conducted deep UV using broad-band femtosecond transient absorption and electronic two-dimensional spectroscopies. found that photodeactivation all occurs two steps: fast relaxation (500–700 fs) from excited state ππ* to a "dark" its depopulation ground within 1–2 ps. Our experimental observations performed theoretical modeling allow us conclude this dark can be associated with nπ* state, which is...
We determined the complete relaxation dynamics of pyrene in ethanol from second bright state, employing experimental and theoretical broadband heterodyne detected transient grating two-dimensional photon echo (2DPE) spectroscopy, using pulses with duration 6 fs covering a spectral range spanning 250 to 300 nm. Multiple lifetimes are assigned conical intersections through cascade electronic states, eventually leading rapid population lowest long-living excited state subsequent slow...
This paper presents a systematic absorption and circular dichroism spectroscopy study of short single strands DNA, from 2 to 20 bases. They are composed sequence-specific nucleobase composition, either adenine (A), thymine (T), or AT repeats. The spectra hypochromism the one show butterfly-shaped spectra. Data analysis conducted on these oligomers provides evidence for formation excitons their delocalization length along strand DNA in relation how many bases involved excitonic coupling. In...
It remains uncertain whether excited electronic state mixing occurs in the flavin cofactor of light-oxygen-voltage-sensing (LOV) domain. In this study, we present transient absorption and femtosecond stimulated Raman spectra both free EL222 binding mononucleotide (FMN). We observed a change shape excited-state around 800 nm S1 after to EL222, alongside relative intensity increase N1-C2 C2═O2 stretching modes spectra. Based on previous calculated geometric differences between ππ* nπ* states,...
The ultrafast excited-state dynamics of flavin mononucleotide (FMN) was monitored upon light irradiation by a hybrid experimental/computational approach.
Time-resolved femtosecond-stimulated Raman spectroscopy (FSRS) provides valuable information on the structural dynamics of biomolecules. However, FSRS has been applied mainly up to nanoseconds regime and above 700 cm
Abstract High-intensity ultrashort X-ray free-electron laser (XFEL) pulses are revolutionizing the study of fundamental nonlinear x-ray matter interactions and coupled electronic nuclear dynamics. To fully exploit potential this powerful tool for advanced spectroscopies, a noninvasive spectral characterization incident stochastic XFEL with high resolution is key requirement. Here we present methodology that combines high-acceptance angle-resolved photoelectron time-of-flight spectroscopy...
We describe the design and provide results of full characterization a closed-loop pump-driven wire-guided flow jet system. The has excellent optical quality with wide range liquids spanning from alcohol to water based solutions, including phosphate buffers used for biological samples. thickness film varies depending on rate between 90 μm 370 μm. liquid is very stable, its only by 0.76% under optimal conditions. Measured transmitted signal reveals long term stability (hours) RMS 0.8%, less...
Time-resolved femtosecond stimulated Raman spectra (FSRS) of a prototypical organometallic photosensitizer/photocatalyst ReCl(CO)3(2,2'-bipyridine) were measured in broad spectral range ∼40-2000 (4000) cm-1 at time delays from 40 fs to 4 ns after 400 nm excitation the lowest allowed electronic transition. Theoretical ground- and excited-state obtained by anharmonic vibrational analysis using second-order perturbation theory on vibrations calculated harmonic approximation density functional...
Abstract X-ray spectroscopy is a demanded tool across multiple user communities. Here we report on new station for emission at the Extreme Light Infrastructure Beamlines Facility. The instrument utilizes von Hamos geometry and works with number of different sample types, notably including liquid systems. We demonstrate simple reliable method source position control using two cameras. This approach addresses energy calibration dependence position, which characteristic measurement uncertainty...
A new modification of a table-top laser-driven water-jet plasma X-ray source has been successfully implemented and commissioned at the Extreme Light Infrastructure (ELI) Beamlines user facility. In order to preserve broadband nature for spectroscopic experiments, polycapillary lens was initially chosen as focusing element. Generally, optics have narrow photon acceptance angle small field view, making alignment complicated time-consuming. This contribution demonstrates straightforward,...
Employing density functional theory (DFT) and time-dependent (TDDFT) calculations in combination with the semiclassical nuclear ensemble method, we have simulated photoabsorption spectra of four canonical DNA nucleobases aqueous solution. In order to model effects solvation, for each nucleobase, a number solvating water molecules were explicitly included simulations, additionally, bulk solvent was represented by continuous polarizable medium. We find that effect solvation shell general is...
We developed an all-reflective fully-noncollinear setup for two-dimensional electronic spectroscopy in the broadband UV (2DUV) with great phase stability (Λ/150) and applied it to UV-chromophores dissolved ethanol using 8-fs UV-pulses, generated 245-300 nm range. are able resolve 2D-spectra ~6000 cm−1 spectral window.
This paper describes performance enhancement developments to a closed-loop pump-driven wire-guided flow jet (WGJ) for ultrafast X-ray spectroscopy of liquid samples. Achievements include dramatically improved sample surface quality and reduced equipment footprint from 7 × 20 cm
Using broadband deep-UV transient absorption and electronic 2D spectroscopies we found that in all DNA nucleobases the photodeactivation of excited-state population occurs two steps via a “dark” state which presumably is nπ* state.
High-intensity ultrashort X-ray free-electron laser (XFEL) pulses are revolutionizing the study of fundamental nonlinear x-ray matter interactions and coupled electronic nuclear dynamics. To fully exploit potential this powerful tool for advanced spectroscopies, a noninvasive spectral characterization incident stochastic XFEL with high resolution is key requirement. Here we present methodology that combines high-acceptance angle-resolved photoelectron time-of-flight spectroscopy ghost...