Institute of Photonics Technology

Albert, Germany

Institute of Photonics Technology

Albert, Germany
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Rothhardt J.,Friedrich - Schiller University of Jena | Rothhardt J.,Helmholtz Institute Lena | Heidt A.,Stellenbosch University | Heidt A.,Institute of Photonics Technology | And 8 more authors.
2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference, CLEO EUROPE/EQEC 2011 | Year: 2011

Supercontinuum generation in photonic crystal fibers (PCF) is a well known method to generate ultra-broad optical spectra which are of great interest for ultra-short pulse compression. By using a PCF with zero dispersion around 800 nm and a SLM based active phase shaping device, compression to 5.5 fs duration has been achieved [1]. However, the coherence of the generated continuum ultimately limits pulse compression [2]. © 2011 IEEE.

Nedbal J.,King's College London | Nedbal J.,Guys Hospital | Hobson P.S.,King's College London | Hobson P.S.,Guys Hospital | And 6 more authors.
PLoS ONE | Year: 2012

We present a web engine boosted fluorescence in-situ hybridization (webFISH) algorithm using a genome-wide sequence similarity search to design target-specific single-copy and repetitive DNA FISH probes. The webFISH algorithm featuring a user-friendly interface ( maximizes the coverage of the examined sequences with FISH probes by considering locally repetitive sequences absent from the remainder of the genome. The highly repetitive human immunoglobulin heavy chain sequence was analyzed using webFISH to design three sets of FISH probes. These allowed direct simultaneous detection of class switch recombination in both immunoglobulin-heavy chain alleles in single cells from a population of cultured primary B cells. It directly demonstrated asynchrony of the class switch recombination in the two alleles in structurally preserved nuclei while permitting parallel readout of protein expression by immunofluorescence staining. This novel technique offers the possibility of gaining unprecedented insight into the molecular mechanisms involved in class switch recombination. © 2012 Nedbal et al.

Abraham S.,Banaras Hindu University | Abraham S.,Friedrich - Schiller University of Jena | Ciobota V.,Friedrich - Schiller University of Jena | Srivastava S.,Banaras Hindu University | And 8 more authors.
Analytical Methods | Year: 2014

The mesoporous silica particle embedded graphene oxide (GO) hybrid system is a promising platform for electrochemical biosensing owing to its large 2-dimensional structure, fast electron transfer kinetics, improved hydrophilic nature and surplus functional groups. Here, GO sheets were synthesized by Hummer's improved method and sub-micron sized homogeneous mesoporous silica (SiO2) particles were prepared by Stober's method. The SiO 2 particles were embedded on the GO surfaces and were optimized with different concentrations for better applicability and hydrophilicity. Micro-structural and spectroscopic characterization of as-synthesized materials was carried out to confirm the successful synthesis as well as the functionalities required for biosensing. Scanning electron microscopy investigations suggest that the average size of the SiO2 particles decorated on the GO surface is ∼500 nm. Raman investigation provides information regarding the increase in defects and disorder on the GO surface with the increase in the SiO2 content. The optimized GO-SiO 2 (GOS) composite electrode was prepared by the electrophoretic deposition technique and was used for the attachment of urease and glutamate dehydrogenase enzymes for urea detection employing the cyclic voltammetry method. The reproducibility, specificity and stability of the fabricated biosensor were found to be excellent for the urea sensing. Such an easy and cost effective material based GOS urea sensor showed a high sensitivity (2.6 μA mM-1 cm-2) and a good detection limit (14 mg dL -1). This journal is © the Partner Organisations 2014.

Muller C.,Babes - Bolyai University | Glamuzina B.,University of Dubrovnik | Pozniak I.,University of Dubrovnik | Weber K.,Friedrich - Schiller University of Jena | And 6 more authors.
Talanta | Year: 2014

Domoic acid (DA) biotoxin responsible for the amnesic shellfish poisoning (ASP) has been unambiguously detected in seawater in a broad range of concentration, with both pure and amino-functionalized Ag nanoparticles employed for surface enhanced Raman scattering (SERS). To achieve this, a comprehensive SERS study on DA dissolved in distilled water has been conducted. SERS of DA dissolved in seawater in concentrations ranging from 3.3×10-4 to 3.3×10-8 mol l-1 exhibited specific signal, completely different to those of the corresponding DA aqueous solutions, due to the seawater interference in the overall SERS effect. In order to assess the capability of the technique as a cheaper alternative for rapid and unambiguous detection of the DA biotoxin in seawater, three detection schemes have been proposed. DA was detectable at 0.33 nmol l-1 concentration (0.33) dissolved in distilled water and 0.033 nmol l-1 (0.033 ppb) in seawater respectively, much lower than the admitted level by the current regulation. A solvent specific interaction of DA with the NPs was concluded, since DA aqueous solution added to Ag nanoparticles provided different SERS signal compared to that of DA directly dissolved in seawater. Employing amino-functionalized Ag nanoparticles with 4-aminothiophenol as SERS tag, SERS signal of DA on amino-AgNPs revealed significant specificity associated with the aromatic primary amine interaction of the SERS tag with DA, thus allowing DA detection in seawater at 4.16×10-4 mol l-1 concentration, much higher than in the case of pure NPs. To highlight the findings, a brief literature review to date on the DA biotoxin detection was also provided. © 2014 Elsevier B.V.

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