Plasmachem GmbH

Berlin, Germany

Plasmachem GmbH

Berlin, Germany
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Goldenberg L.M.,Wildau University of Applied Sciences | Goldenberg L.M.,Plasmachem GmbH | Lisinetskii V.A.,Wildau University of Applied Sciences | Schrader S.,Wildau University of Applied Sciences
Laser Physics | Year: 2014

Two simple procedures to manufacture continuously tunable miniature lasers in azobenzene-containing material were developed. Both types of lasers rely on the distributed feedback provided by polarization gratings. In a first approach tuning is achieved by changing the thickness of the active wave guiding layer by means of a wedge layer and in a second approach by gradually changing the spatial frequency of the refractive index grating obtained by modification of the Lloyd interferometer set-up used for holographic inscription of the gratings. A continuous tuning range of up to 35 nm has been demonstrated. © 2014 Astro Ltd.

Goldenberg L.M.,Plasmachem GmbH | Lisinetskii V.,Wildau University of Applied Sciences | Ryabchun A.,Fraunhofer Institute for Applied Polymer Research | Ryabchun A.,Moscow State University | And 2 more authors.
Journal of Materials Chemistry C | Year: 2014

The well-known commercially available azobenzene-containing polyelectrolyte poly{1-[4-(3-carboxy-4-hydroxyphenylazo)benzenesulfonamido]-1,2-ethanediyl, sodium salt} (PAZO-Na) has been easily modified by converting it into carboxylic acid and different salts. These new materials, similar to original PAZO-Na, were used as matrices to create DFB lasers based on polarization gratings. Such matrix modification allowed us to obtain laser generation with the laser dye 1,2,3,5,6,7-hexamethyl-8-cyanopyrromethene-difluoroborate complex (pyrromethene 650), to increase the laser device stability (up to a half-life time of 4 × 104pulses) and to considerably increase the laser efficiency (up to 9%). Therefore, these polymer composites can be considered as cheap and promising materials for photonics, optoelectronics, and sensor applications. © the Partner Organisations 2014.

Goldenberg L.M.,Wildau University of Applied Sciences | Goldenberg L.M.,Plasmachem GmbH | Lisinetskii V.,Wildau University of Applied Sciences | Schrader S.,Wildau University of Applied Sciences
Advanced Optical Materials | Year: 2014

Using amorphous side-chain azobenzene-containing polymers, stable and efficient miniature lasers based on polarization gratings as distributed feedback are fabricated. The lasers with Rhodamine 700 dye as the emitter exhibit a low lasing threshold of ca. 20 μJ cm-2, which is even further decreased to ca. 5-10 μJ cm-2 for the devices emitting in the 1st diffraction order. Additionally this new formulation exhibits a considerably higher efficiency of ca. 3%, and a higher half-life of more than 1 × 105 shots. A wide wavelength tuning range of 115 nm is obtained for the same formulation only by changing grating frequency. A variation of polymer matrix, laser dye, and grating spatial frequency allows an extended tuning range between 611 and 873 nm. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Goldenberg L.M.,Plasmachem GmbH | Lisinetskii V.,Wildau University of Applied Sciences | Schrader S.,Wildau University of Applied Sciences
Applied Physics B: Lasers and Optics | Year: 2015

An efficient organic vertical-cavity surface-emitting laser with spin-coated polymeric mirrors is demonstrated. Being pumped with the wavelength of 532 nm, the laser generates pulses with the wavelength of 670 nm and the pulse energy of 32 µJ. The slope efficiency of 22 % was obtained for the laser. © 2015, Springer-Verlag Berlin Heidelberg.

Goldenberg L.M.,Wildau University of Applied Sciences | Goldenberg L.M.,Plasmachem GmbH | Lisinetskii V.,Wildau University of Applied Sciences | Ryabchun A.,Fraunhofer Institute for Applied Polymer Research | And 3 more authors.
ACS Photonics | Year: 2014

For the first time a liquid crystalline azobenzene-containing side-chain copolymer was employed as matrix material for distributed feedback lasers based on orientation gratings. Effective polarization gratings with periods of 245-290 nm could be inscribed within just one second using moderate light intensity. Using a number of near-infrared laser dyes and different grating frequencies, tuning of wavelength of the emitted radiation from 760 to 883 nm was obtained. It was also found that the lasing wavelength depends on the angle between the liquid crystal director and the grating vector. Wavelength tuning in the range of 30 nm was demonstrated using this method. © 2014 American Chemical Society. (Figure Presented).

PubMed | University of Genoa, University of Limerick, PlasmaChem GmbH and Italian Institute of Technology
Type: Journal Article | Journal: PloS one | Year: 2014

Cell-sized polyelectrolyte capsules functionalized with a redox-driven proton pump protein were assembled for the first time. The interaction of polyelectrolyte microcapsules, fabricated by electrostatic layer-by-layer assembly, with cytochrome c oxidase molecules was investigated. We found that the cytochrome c oxidase retained its functionality, that the functionalized microcapsules interacting with cytochrome c oxidase were permeable and that the permeability characteristics of the microcapsule shell depend on the shell components. This work provides a significant input towards the fabrication of an integrated device made of biological components and based on specific biomolecular functions and properties.

Mehdizadeh A.,Shiraz University of Medical Sciences | Pandesh S.,Shiraz University of Medical Sciences | Shakeri-Zadeh A.,Tehran University of Medical Sciences | Kamrava S.K.,Tehran University of Medical Sciences | And 7 more authors.
Lasers in Medical Science | Year: 2014

The use of lasers has emerged to be highly promising for cancer therapy modalities, most commonly, the photothermal therapy method. Unfortunately, the most common disadvantage of laser therapy is its nonselectivity and requirement of high power density. The use of plasmonic nanoparticles as highly enhanced photoabsorbing agents has thus introduced a much more selective and efficient cancer therapy strategy. In this study, we aimed to demonstrate the selective targeting and destruction of mouth epidermal carcinoma cells (KB cells) using the photothermal therapy of folate-conjugated gold nanorods (F-GNRs). Considering the beneficial characteristics of GNRs and overexpression of the folate receptor by KB cells, we selected F-GNRs as a targeted photothermal therapy agent. Cell viability was evaluated using a 3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide assay. Apoptosis was determined by flow cytometry using an annexin V-fluorescein isothiocyanate/propidium iodide apoptosis detection kit. No cell damage or cytotoxicity from the individual treatment of laser light or F-GNRs was observed. However, a 56 % cell lethality was achieved for KB cells using combined plasmonic photothermal therapy of 20 μM F-GNRs with seven pulses of laser light and 6-h incubation periods. Cell lethality strongly depends on the concentration of F-GNRs and the incubation period that is mainly due to the induction of apoptosis. This targeted damage is due to the F-GNRs present in the cancer cells strongly absorbing near-infrared laser light and rapidly converting it to heat. This new therapeutic avenue for cancer therapy merits further investigation using in vivo models for application in humans. © 2013 Springer-Verlag.

PubMed | Italian Institute of Technology and Plasmachem GmbH
Type: | Journal: Scientific reports | Year: 2016

We propose and demonstrate a novel subtraction microscopy algorithm, exploiting fluorescence emission difference or switching laser mode and their derivatives for image enhancement. The key novelty of the proposed approach lies in the weighted subtraction coefficient, adjusted pixel-by-pixel with respect to the intensity distributions of initial images. This method produces significant resolution enhancement and minimizes image distortions. Our theoretical and experimental studies demonstrate that this approach can be applied to any optical microscopy techniques, including label free and non-linear methods, where common super-resolution techniques cannot be used.

Severin N.,Humboldt University of Berlin | Dorn M.,Humboldt University of Berlin | Kalachev A.,PlasmaChem GmbH | Rabe J.P.,Humboldt University of Berlin
Nano Letters | Year: 2011

The electronic properties of graphenes depend sensitively on their deformation, and therefore strain engineered graphene electronics is envisioned.(1-3)In order to deform graphenes locally, we have mechanically exfoliated single and few layer graphenes onto atomically flat mica surfaces covered with isolated double stranded plasmid DNA rings. Using scanning force microscopy in both contact and intermittent contact modes, we find that the graphenes replicate the topography of the underlying DNA with high precision. The availability of macromolecules of different topologies, e.g., programmable DNA patterns,(4)render this approach promising for new graphene based device designs.(1, 3)On the other hand, the encapsulation of single macromolecules offers new prospects for analytical scanning probe microscopy techniques. © 2011 American Chemical Society.

PubMed | University of Bordeaux 1 and PlasmaChem GmbH
Type: | Journal: Journal of proteome research | Year: 2016

Thorough characterization of toxic effects of nanoparticles (NP) is desirable due to the increasing risk of potential environmental contamination by NP. In the current study, we combined three recently developed proteomics approaches to assess the effects of Au, CuO, and CdTe NP on the innate immune system. The human monocyte cell line THP-1 was employed as a model. The anticancer drugs camptothecin and doxorubicin were used as positive controls for cell death, and lipopolysaccharide was chosen as a positive control for proinflammatory activation. Despite equivalent overall toxicity effect (50 10% dead cells), the three NP induced distinctly different proteomics signatures, with the strongest effect being induced by CdTe NP, followed by CuO and gold NP. The CdTe toxicity mechanism involves down-regulation of topoisomerases. The effect of CuO NP is most reminiscent of oxidative stress and involves up-regulation of proteins involved in heat response. The gold NP induced up-regulation of the inflammatory mediator, NF-B, and its inhibitor TIPE2 was identified as a direct target of gold NP. Furthermore, gold NP triggered activation of NF-B as evidenced by phosphorylation of the p65 subunit. Overall, the combined proteomics approach described here can be used to characterize the effects of NP on immune cells.

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