A5016952206- Polymer Surface Interaction Studies
- Photochemistry and Electron Transfer Studies
- Dendrimers and Hyperbranched Polymers
- Advanced biosensing and bioanalysis techniques
- Spectroscopy and Quantum Chemical Studies
- X-ray Diffraction in Crystallography
- Strong Light-Matter Interactions
- Crystallization and Solubility Studies
- Membrane Separation Technologies
- Analytical Chemistry and Sensors
- Molecular Junctions and Nanostructures
- Porphyrin and Phthalocyanine Chemistry
- Advanced Biosensing Techniques and Applications
- Nonlinear Optical Materials Research
- Photonic and Optical Devices
- Nanoparticle-Based Drug Delivery
- Lipid Membrane Structure and Behavior
- Surface Modification and Superhydrophobicity
- Luminescence and Fluorescent Materials
- RNA Interference and Gene Delivery
- Electrospun Nanofibers in Biomedical Applications
- Thermal Radiation and Cooling Technologies
- Photonic Crystals and Applications
- Protein Interaction Studies and Fluorescence Analysis
- Surfactants and Colloidal Systems
Surflay Nanotec (Germany)
2014-2024
Center for NanoScience
2002-2009
RWTH Aachen University
2008
Åbo Akademi University
2008
University of Turku
2008
Max Planck Institute of Colloids and Interfaces
1997-2003
Max Planck Society
1997-2003
Freie Universität Berlin
1995-2001
Philipps University of Marburg
2001
Johannes Gutenberg University Mainz
1998
Layer-by-layer (LbL) assembly is a widely used tool for engineering materials and coatings. In this Perspective, dedicated to the memory of ACS Nano associate editor Prof. Dr. Helmuth Möhwald, we discuss developments applications that are come in LbL assembly, focusing on coatings, bulk materials, membranes, nanocomposites, delivery vehicles.
A defined and controllable permeability of the capsule wall hollow polyelectrolyte capsules has been achieved. The walls these can be switched between an open a closed state with respect to macromolecules by adjusting salt concentration solution in which are dispersed. Figure shows part mechanism encapsulate release this method.
Hollow polyelectrolyte capsules in micro- and submicrometer size were prepared. Their interior was functionalized by a "ship bottle" synthesis of copolymers. While the monomers permeated capsule wall easily, formed polymers remained cage. The physicochemical properties such as ion strength, pH, light absorption, fluorescence could be controlled independently from surrounding solvent means chemical nature captured polymer. In case polyelectrolytes osmotic pressure counterions led to swelling...
Cryo-transmission electron microscopy (cryo-TEM), absorption spectroscopy with polarized light, and polarized-light optical have been used to characterize the J-aggregates formed by dye 1,1'-diethyl-2,2'-cyanine chloride (pseudoisocyanine chloride) in aqueous solution. Cryo-TEM visualizes for first time directly rodlike morphology of J-aggregates. A rod diameter 2.3 ± 0.2 nm is estimated. Absorption shows that J-aggregation a strong function concentration starts dilute solution before...
Hollow polyelectrolyte capsules have been recently introduced as a novel type of artificial smart material. Here is reported the successful filling based on human erythrocytes with various dye compounds using method selective precipitation. Control surface properties and conditions leads to preferential crystallization in interior capsules, shown schematically Figure.
The influence of thermal treatment on the permeability polyelectrolyte multilayer capsules is studied via confocal fluorescence microscopy individual microcapsules. For specific most frequently used example, made poly(styrenesulfonic acid) and poly(allylamine hydrochloride), penetration fluorescein shown to be reduced by 3 orders magnitude heating at 80 °C. data show that holes formed during preparation may annealed in a predictable way.
Gold nanoparticle layers (AuNPLs) enable the coupling of morphological, optical, and electrical properties gold nanoparticles (AuNPs) with tailored specific surface topography, making them exploitable in many bioapplications (e.g., biosensing, drug delivery, photothermal therapy). Herein, we report formation AuNPLs on porous silicon (PSi) interferometers distributed Bragg reflectors (DBRs) for (bio)sensing applications via layer-by-layer (LbL) nanoassembling a positively charged...
Abstract Gegenstand dieses Aufsatzes sind neuartige Polyelektrolyt‐Mikrokapseln, einschließlich ihrer Herstellung und Eigenschaften, insbesondere im Hinblick auf ihre mechanischen Permeationseigenschaften. Die problemlose Präparation durch einen Layer‐by‐Layer‐Selbstorganisationsprozess, die präzise Kontrolle der Wandstärke Flexibilität bei Wahl Einzelkomponenten machen Kapseln für Anwendungen Life‐Science‐Bereich in den Materialwissenschaften interessant. Darüber hinaus können ein...
Cholesterol-based lipophilic oligonucleotides incorporated into lipid membranes were studied using solid-state NMR, differential scanning calorimetry, and fluorescence methods. Lipophilic can be used to build nanotechnological structures on membrane surfaces, taking advantage of the specific Watson-Crick base pairing. We a cholesteryl-TEG anchor first described by Pfeiffer Hook (J. Am. Chem. Soc. 2004, 126, 10224-10225). The cholesterol-based molecules found incorporate well without...
Poly(styrene sulfonate) and poly(allylamine hydrochloride) layers have been adsorbed supplementarily on polyelectrolyte capsules. The permeability of the original capsules consisting four layer pairs was order 10–5 m/s for fluorescein. They were also permeable macromolecules. Polyelectrolyte afterwards reduced by three orders magnitude small molecules. These findings are interpreted as a resealing pores, induced osmotic stress during fabrication.
Polymeric capsules possessing a shell-in-shell structure were fabricated by assembling layers of polyelectrolytes with interlayers silica nanoparticles onto microspheres melamine formaldehyde. Subsequently the cores removed hydrochloric acid and hydrofluoric acid. Removal leaves an aqueous phase poly(allylamine hydrochloride) solution between outer inner polyelectrolyte shell. The interlayer thickness could be varied diameter particles or number deposition steps. double-shell microcapsules...
Functionalization of the interior hollow microcapsules with polyelectrolytes allows preparation supramolecular dye assemblies inside capsules (see Figure). The J‐aggregates can be transformed into nanocrystals by diffusion hydrophobic counterions in capsules, resulting strong changes luminescence behavior.
H-aggregates of the cyanine dye Cy5 are formed during covalent linkage to cationic macromolecule Poly(allylamine) (PAH). The nonfluorescent strongly restrict usage for analytical purposes and prevent a quantitative determination labeled macromolecules. behavior has been studied by investigation absorption fluorescence spectra polymer in dependence on solvent, label degree additional sulfonate groups. H-aggregate formation is caused an inhomogeneous distribution molecules chain. can be...
Abstract An efficient and easy‐to‐use approach is presented for obtaining biocompatible polysaccharide‐based nanoparticles (NP) that can act as tumor‐specific drug delivery agents. Two antibodies are directly immobilized onto reactive xylan phenyl carbonate (XPC) NP; namely Cetuximab (CTX) binds to human epidermal growth factor receptor (EGFR) Atezolizumab (ATZ) programmed death‐ligand 1 (PD‐L1). High coupling efficiency (up 100 %) achieved without any pre‐activation no aggregation occurs...
A variety of light-harvesting capsules were successfully constructed by assembling polyelectrolyte complexes and antenna dyes graduated absorption energy into nanoscale walls (thickness a single layer around 2 nm). Two-step downhill transfer was demonstrated with fluorescence spectroscopy for the first time on capsules. Energy occurs parallel to capsule surface if are coadsorbed preassembled wall. perpendicular achieved sequentially in different layers Although is less efficient because...
A two-step energy transfer cascade was constructed in the wall of hollow microcapsules by means defined assembly three cyanine dyes, thiacyanine (antenna), thiacarbocyanine (receiver and antenna), indodicarbocyanine (receiver), plane perpendicular to it. The efficiency steps has been measured fluorescence spectroscopy. unidirectional surface smaller than for lateral one. antenna dyes on outer capsules harvest light conduct it downhill Förster resonance capsule interior analogy chloroplasts...
Microscopic colloidal particles allow a precise regulation of chemical reactions in time and place. A controlled assembly multiple layers intact lipid vesicles on solid support provided by layer-by-layer functionalized covalent attachment DNA oligonucleotides is reported (see image). Lipophilic complementary are incorporated into vesicles. Fusion liposomes release can be triggered.