WITec GmbH

Neu-Ulm, Germany

WITec GmbH

Neu-Ulm, Germany
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Tescan Orsay Holding a.s. and Witec GmbH | Date: 2015-09-30

The invention relates to system using number of analytical devices such as electron microscope (4), Raman microscope (6), ion beam column (20) and scanning probe microscope (24) for sample (3) analysis concurrent, consecutive or with the mutual correlation of the analysis performed by the different devices in the same sample (3) area using the connection of the Raman microscope optical objective lens (11) and objective manipulator (17), that significantly reduces time needed for analyzing by Raman microscope (6) together with other devices and maintains high quality of the sensed signals comparable to stand alone analytical devices.

WITec GmbH and TESCAN ORSAY HOLDING a.s. | Date: 2015-03-24

A system uses number of analytical devices such as an electron microscope a Raman microscope, an ion beam column and a scanning probe microscope for sample analysis concurrent, consecutive or with the mutual correlation of the analysis performed by the different devices in the same sample area using the connection of the Raman microscope optical objective lens and objective manipulator, that significantly reduces time needed for analyzing by Raman microscope together with other devices and maintains high quality of the sensed signals comparable to stand alone analytical devices.

Sun S.,CAS National Center for Nanoscience and Technology | Thompson D.,University of Strathclyde | Schmidt U.,WiTec GmbH | Graham D.,University of Strathclyde | Leggett G.J.,Krebs Institute
Chemical Communications | Year: 2010

Hybridisation of oligonucleotide micro- and nano-structures, formed using far- and near-field optical lithography, with Raman dye-labelled silver nanoparticles functionalised with complementary oligonucleotides yields striking contrast, attributed to Raman "hot-spot" formation, and enables rapid, convenient read-out by Raman microscopy. © 2010 The Royal Society of Chemistry.

Millar R.W.,University of Glasgow | Gallacher K.,University of Glasgow | Samarelli A.,University of Glasgow | Frigerio J.,Polytechnic of Milan | And 4 more authors.
Optics Express | Year: 2015

The room temperature photoluminescence from Ge nanopillars has been extended from 1.6 μm to above 2.25 μm wavelength through the application of tensile stress from silicon nitride stressors deposited by inductively-coupled-plasma plasma-enhanced chemical-vapour-deposition. Photoluminescence measurements demonstrate biaxial equivalent tensile strains of up to ∼1.35% in square topped nanopillars with side lengths of 200 nm. Biaxial equivalent strains of 0.9% are observed in 300 nm square top pillars, confirmed by confocal Raman spectroscopy. Finite element modelling demonstrates that an all-around stressor layer is preferable to a top only stressor, as it increases the hydrostatic component of the strain, leading to an increased shift in the band-edge and improved uniformity over top-surface only stressors layers. © 2015 Optical Society of America.

Sahu A.,Chilakapati Laboratory | Sawant S.,Tata Memorial Center | Mamgain H.,WITec GmbH | Krishna C.M.,Chilakapati Laboratory
Analyst | Year: 2013

Early diagnosis of oral cancers, one of the major cancers, is of utmost importance as 5-year disease-free survival rates are some of the lowest, despite advances in treatment and surgical modalities. In vivo Raman spectroscopy has shown efficacy in the detection of normal, premalignant and malignant lesions and even of early changes such as cancer-field-effects/malignancy-associated- changes. However, the need for a dedicated instrument and stringent laboratory conditions, at all diagnostic centers, limits wide screening applications of this method. In light of this, it is pertinent to explore ex vivo samples like serum due to its ease of collection, storage, transport and analysis at a centralized facility. Hence, Raman studies were carried out on serum from 14 buccal mucosa and 40 tongue cancers as well as 16 healthy control samples. Spectral features indicate differential contributions of proteins, DNA, and amino acids like Phe, Trp and Tyr and p-carotene in the analyzed groups. Highly intense Raman bands assigned to p-carotene could be due to resonance Raman, and were observed in all sera with the highest relative intensity in normal samples. Higher DNA and protein content were observed in the mean cancer spectra. Principal component-linear discriminant analysis (PC-LDA) followed by cross-validation using leave-one-out cross-validation (LOOCV) were employed for data analysis which was carried out both spectra- and patient-wise. Findings indicate the possibility of classifying normal and oral cancer sera in both these approaches; however, the patient-wise approach could be the preferred mode for prospective studies. Besides, a tendency of classification for buccal mucosa and tongue cancers was also observed. Prospective validation of these results on a large sample size may help in the translation of this methodology to clinics. © The Royal Society of Chemistry 2013.

Mikhno A.O.,RAS Institute of Geology and Mineralogy | Schmidt U.,WITec GmbH | Korsakov A.V.,RAS Institute of Geology and Mineralogy
European Journal of Mineralogy | Year: 2013

Confocal Raman Imaging revealed the coexistence of kokchetavite and K-cymrite (KAlSi3O8·H2O) in association with muscovite/phengite, lollingite, calcite and α-cristobalite in polyphase mineral inclusions in clinopyroxene of calc-silicate ultrahighpressure metamorphic (UHPM) rocks from the Kokchetav Complex (northern Kazakhstan). Experiments have shown that K-cymrite is stable under high pressure conditions; however, this phase never had been reported from UHPM rocks before. The mode of occurrence of K-cymrite and kokchetavite in these rocks is strong evidence for kokchetavite formation through the dehydration of K-cymrite. The presence of fluid inclusions and K-cymrite in the polyphase mineral inclusions testify for water-saturated conditions in the rock-forming environment near peak metamorphic conditions. © 2013 E. Schweizerbart'sche Verlagsbuchhandlung, D-70176 Stuttgart.

Buch Z.,Luminescent | Kumar V.,Luminescent | Mamgain H.,WITec GmbH | Chawla S.,Luminescent
Journal of Physical Chemistry Letters | Year: 2013

A silver nanoprism (Ag NP) generates a near field due to multipolar surface plasmon resonance (SPR) and lightening rod effects and acts as a multipolar nanoantenna. The ability of Ag NPs to create such an effect even under an infrared (IR) optical field far off of resonance from the SPR frequency is demonstrated through finite difference time domain simulations of exact Ag NPs and hybrids. The conclusive experimental proof of such a near field around Ag NPs under low-intensity (1.5 mW) IR (980 nm) light came when it could excite fluorescence from YVO4/Eu3+ nanoparticles that otherwise do not fluoresce under IR. The results open up new vistas for exclusive plasmonic excitation of fluorescence through metal NP hybrids/ensembles. © 2013 American Chemical Society.

Rusciano G.,University of Naples Federico II | Zito G.,University of Naples Federico II | Isticato R.,University of Naples Federico II | Sirec T.,University of Naples Federico II | And 3 more authors.
ACS Nano | Year: 2014

Tip-enhanced Raman Scattering (TERS) has recently emerged as a powerful spectroscopic technique capable of providing subdiffraction morphological and chemical information on samples. In this work, we apply TERS spectroscopy for surface analysis of the Bacillus subtilis spore, a very attractive biosystem for a wide range of applications regulated by the spore surface properties. The observed spectra reflect the complex and heterogeneous environment explored by the plasmonic tip, therefore exhibiting significant point-to-point variations at the nanoscale. Herein, we demonstrate that TERS data processing via principal component analysis allows handling such spectral changes, thus enabling an unbiased correlative imaging based on TERS. Our experimental outcomes suggest a denser arrangement of both proteins and carbohydrates on specific spore surface regions simultaneously revealed by AFM phase imaging. Successful TERS analysis of spores surface is useful for bacterial surface-display systems and drug delivery applications. © 2014 American Chemical Society.

Rosner B.,Friedrich - Alexander - University, Erlangen - Nuremberg | Zeilmann N.,Friedrich - Alexander - University, Erlangen - Nuremberg | Schmidt U.,Witec GmbH | Fink R.H.,Friedrich - Alexander - University, Erlangen - Nuremberg
Organic Electronics: physics, materials, applications | Year: 2014

Ultrathin pentacene films resemble benchmark and model materials for organic field-effect transistors (OFETs). We employ scanning transmission X-ray microspectroscopy (STXM) and confocal Raman microspectroscopy as highly resolving probes to obtain insight into the correlation of morphology and charge transport in pentacene OFETs. By combining the operation-induced intensity increase in Raman-active bands with micromorphology, we are able to visualize charge-induced effects, in particular charge trapping in pentacene OFETs during operation. The high sensitivity and specificity of Raman microscopy allows to distinguish between orientation and charge-induced effects and thus to locate the trapped charges at grain boundaries.© 2013 Elsevier B.V. All rights reserved.

Buch Z.,Luminescent | Kumar V.,Luminescent | Mamgain H.,WITec GmbH | Chawla S.,Luminescent
Chemical Communications | Year: 2013

Silver nanoprisms of different sizes influence fluorescence enhancement in YVO4:Eu3+ nanoparticles to various degrees under excitation of green light (532 nm). The local field generated by silver nanoprisms and their dimers is simulated through the FDTD method and a direct correlation with fluorescence enhancement is established. © 2013 The Royal Society of Chemistry.

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