A5013084256- Molecular Junctions and Nanostructures
- Spectroscopy Techniques in Biomedical and Chemical Research
- Analytical Chemistry and Sensors
- Spectroscopy and Quantum Chemical Studies
- Polymer Surface Interaction Studies
- Force Microscopy Techniques and Applications
- Conducting polymers and applications
- Semiconductor materials and devices
- Advanced biosensing and bioanalysis techniques
- Electrochemical Analysis and Applications
- Optical Polarization and Ellipsometry
- Quantum Dots Synthesis And Properties
- Graphene research and applications
- Silicon Nanostructures and Photoluminescence
- Surfactants and Colloidal Systems
- Nonlinear Optical Materials Research
- Gold and Silver Nanoparticles Synthesis and Applications
- Plasmonic and Surface Plasmon Research
- Surface and Thin Film Phenomena
- Semiconductor Quantum Structures and Devices
- Organic Electronics and Photovoltaics
- Spectroscopy and Chemometric Analyses
- Liquid Crystal Research Advancements
- Ion-surface interactions and analysis
- Spectroscopy and Laser Applications
Helmholtz-Zentrum Berlin für Materialien und Energie
2009-2025
Leibniz Institute for Analytical Sciences - ISAS
2015-2024
Humboldt-Universität zu Berlin
2022
King Abdullah University of Science and Technology
2019
Leibniz Institute for Neurobiology
2010-2015
Institut des Sciences Analytiques
2006-2009
Bulgarian Academy of Sciences
2008-2009
Hasselt University
2008
Leibniz Institute of Polymer Research
2002-2008
Sandia National Laboratories
2008
Identification of electronic processes at buried interfaces charge-selective contacts is crucial for photovoltaic and photocatalysis research. Here, transient surface photovoltage (SPV) used to study the passivation different hole-selective carbazole-based SAMs. It shown that SPV photoluminescence provide complementary information on charge transfer kinetics trapping/de-trapping mechanisms, trap-assisted non-radiative recombination losses originate from electron trapping SAM-modified...
2D mussel-inspired polydopamine (PDA) nanosheets are prepared and exploited as a functional surface for grafting various polymer brushes. The PDA nanosheet its polymer-brush derivatives show lateral integrity robust; therefore, they can be detached from their substrates. Cell-adhesion tests that the promotes cell growth attachment, while PDA-based poly(3-sulfopropyl methacrylate) carpet exhibits nonfouling behavior. As service to our authors readers, this journal provides supporting...
Abstract Dysregulation of extracellular signal-regulated kinases (ERK1/2) is linked to several diseases including heart failure, genetic syndromes and cancer. Inhibition ERK1/2, however, can cause severe cardiac side-effects, precluding its wide therapeutic application. ERK T188 -autophosphorylation was identified pathological hypertrophy. Here we report that interference with ERK-dimerization, a prerequisite for -phosphorylation, minimizes hypertrophy without inducing adverse effects: an...
Solvated electrons are highly reductive chemical species whose properties remain largely unknown. Diamond materials proposed as a promising emitter of solvated and visible light excitation would enable solar-driven CO2 or N2 reductions reactions in aqueous medium. But sub-bandgap remains challenging. In this work, the role surface states on diamond for charge separation emission both gaseous environments from deep UV to is elucidated. Four different X-ray UV-vis spectroscopy methods applied...
Abstract Nanodomains formed by microphase separation in thin films of the diblock copolymers poly(styrene‐ b ‐2‐vinylpyridine) (PS‐ ‐P2VP) and ‐ethyleneoxide) ‐PEO) were imaged means infrared scattering‐type near‐field microscopy. When probing at 3.39 μm (2950 cm − 1 ), contrast is obtained due to spectral differences between C H stretching vibrational resonances respective polymer constituents. An all‐optical spatial resolution better than 10 nm was achieved, which corresponds a...
The irradiation-induced reduction of electrochemically grafted nitrobenzene films on Si(111) was monitored by high-resolution photoelectron spectroscopy. experiments were performed using synchrotron soft X-ray irradiation at the BESSY II facility. evolution different chemical species as a function time. Careful fitting Si2p, C1s, N1s, and O1s core level spectra allowed us to follow this process in detail determine constants growth decay specific components. changes caused secondary electron...
The pH-dependent switching of a poly(acrylic acid) (PAA) polyelectrolyte brush was investigated in situ using infrared spectroscopic ellipsometry (IRSE). synthesized by "grafting to" procedure on silicon substrate with native oxide layer. overall thickness the PAA dry state ∼5 nm. Reversible polymer studied at titration from pH 2 to 10 and back steps 1 unit. process observed monitoring characteristic vibrational bands carboxylic groups molecules. Decreasing C═O band amplitude arising COO−...
Abstract The ability to vary, adjust, and control hydrophobic interactions is crucial in manipulating between biological objects the surface of synthetic materials aqueous environment. To this end a grafted polymer layer (multi‐component mixed brush) synthesized that capable reversibly exposing nanometer‐sized fragments at its hydrophilic tuning, turning on, off interactions. reversible switching occurs response changes environment alters strength range attractive or amphiphilic probes...
The synergistic effect of combining molecular imprinting and surface acoustic wave (SAW) technologies for the selective label-free detection sulfamethizole as a model antibiotic in aqueous environment was demonstrated. A molecularly imprinted polymer (MIP) (SMZ) recognition prepared form homogeneous thin film on sensing surfaces SAW chip by oxidative electropolymerization m-phenylenediamine (mPD) presence SMZ, acting template. Special attention paid to rational selection functional monomer...
The early growth stages of palladium (Pd) on Si(001) are studied in situ by reflectance anisotropy spectroscopy and Raman ultrahigh vacuum. Two vicinal samples with different degrees surface ordering investigated, revealing a distinct Volmer–Weber‐type behavior. Ex atomic force microscopy shows an inhomogeneous covered islands the less‐ordered substrate, while complex layer circular structures related to nucleation‐controlled phase transition as previously reported is found well‐ordered...
We investigate the optical and morphological effects of silver island films exposed to atmosphere. Silver nanoparticles with an average radius below 5 nm were highly tarnished after one week, showing significant changes. Using x-ray photoelectron spectroscopy we demonstrate that tarnishing is predominantly caused by oxidation not sulfidation for nanostructures under normal conditions. Post-deposition annealing nanoparticle results in further changes which are dependent on exposure time...
The protein-adsorbing and -repelling properties of various smart nanometer-thin polymer brushes containing poly(N-isopropylacrylamide) poly(acrylic acid) with high potential for biosensing biomedical applications are studied by in situ infrared-spectroscopic ellipsometry (IRSE). IRSE is a highly sensitive nondestructive technique that allows protein adsorption on to be investigated an aqueous environment as external stimuli, such temperature pH, varied. These changes relevant conditions...
Infrared techniques enable nondestructive and label-free studies of thin films with high chemical structural contrast. In this work, we review recent progress perspectives in the nanoscale analysis anisotropic materials using an extended version atomic force microscopy-infrared (AFM-IR) technique. This advanced photothermal technique, includes polarization control incoming light bridges gap IR spectroscopic local material properties. Such anisotropy occurs a wide range during molecular...
Anisotropic Ag nanoparticle arrays were created by metal evaporation on rippled silicon templates for sensing of molecules with surface-enhanced Raman spectroscopy. Our results show that these substrates can be used analysis complex molecular mixtures and discrimination solvent molecules. These properties are due to their polarization wavelength dependency provide enhancement in a wide spectral range. The dielectric function parallel perpendicular the long axis nanostructures was determined...
Modern infrared (IR) spectroscopic methods as in situ IR ellipsometry (in IRSE) and the photothermal atomic force microscopy (AFM)‐IR technique are introduced novel analysis for characterization of polydopamine (PDA) films. The visible (VIS) ellipsometric studies serve determination thicknesses, optical constants discussion specific vibrational bands. (IRSE) thin film growth (PDA), a versatile material bioactive surfaces, tris(hydroxymethyl)aminomethane (Tris) buffer solution used to monitor...
The switching behavior of stimuli-responsive mixed polymer brushes (d = 11 nm) was monitored for the first time in liquid phase situ by infrared spectroscopic ellipsometry (IRSE). IRSE is presented as a new, sensitive tool online analysis chemical changes thin complex film at solid/liquid interface. Responsive (protonation and deprotonation reaction) poly(acrylic acid)/poly(2-vinylpyridine) (PAA-mix-P2VP) brush probed aqueous solutions with pH ranging from 2 to 10. Structural layer were...
This work provides direct chemical and structural insight into pH-dependent changes of an ultrathin (d=12 nm) mixed polyelectrolyte brush. In-situ infrared spectroscopic ellipsometry was used for the first time to study gradual pH-responsive behavior brush, constituted weak anionic cationic polyelectrolytes, poly(acrylic acid) (PAA) poly(2-vinylpyridine) (P2VP), respectively. The fingerprints in mid-infrared spectral range were analyzed as a function brush caused by pH changes. Thereby, IR...