Hybrid inorganic/organic photonic crystal biochips for cancer biomarkers detection

We report on hybrid inorganic/organic one-dimensional photonic crystal biochips sustaining Bloch surface waves. The biochips were used, together with an optical platform operating in a label-free and fluorescence configuration simultaneously, to detect the cancer biomarker Angiopoietin 2 in a protein base buffer. The hybrid photonic crystals embed in their geometry a thin functionalization poly-acrylic acid layer deposited by plasma polymerization, which is used to immobilize a monoclonal antibody for highly specific biological recognition. The fluorescence operation mode is described in detail, putting into evidence the role of field enhancement and localization at the photonic crystal surface in the shaping and intensification of the angular fluorescence pattern. In the fluorescence operation mode, the hybrid biochips can attain the limit of detection 6 ng/ml.We report on hybrid inorganic/organic one-dimensional photonic crystal biochips sustaining Bloch surface waves. The biochips were used, together with an optical platform operating in a label-free and fluorescence configuration simultaneously, to detect the cancer biomarker Angiopoietin 2 in a protein base buffer. The hybrid photonic crystals embed in their geometry a thin functionalization poly-acrylic acid layer deposited by plasma polymerization, which is used to immobilize a monoclonal antibody for highly specific biological recognition. The fluorescence operation mode is described in detail, putting into evidence the role of field enhancement and localization at the photonic crystal surface in the shaping and intensification of the angular fluorescence pattern. In the fluorescence operation mode, the hybrid biochips can attain the limit of detection 6 ng/ml

Untersuchungen zur spontanen Emission von organischen Farbstoffmolekülen in Schichtsystemen

Gegenstand der Dissertation ist die Fluoreszenz von organischen Farbstoffmolekülen, die in oder in der Nähe von Schichtsystemen angeordnet sind. Dafür wird mit der Methode der Greenschen Funktion zunächst eine klassisch elektrodynamische Beschreibung der Fluoreszenz eines Emitters im Schichtsystem weiterentwickelt, um das Strahlungsfeld und die Lebensdauer der Fluoreszenzemission zu beschreiben. Diese theoretischen Vorhersagen werden an Ensembles von Farbstoffmolekülen experimentell überprüft. Für die Messung der Fluoreszenzlebensdauer wird eine modifizierte Box-Car-Methode vorgestellt, welche die korrekte Lebensdauermessung unabhängig von Bleicheffekten gestattet. Es wird demonstriert, dass die Parameter der optischen Anregungs- und Nachweissysteme das experimentell beobachtete zeitliche Verhalten der Fluoreszenz molekularer Ensembles in einem Schichtsystem beeinflussen

Untersuchungen zur spontanen Emission von organischen Farbstoffmolekülen in Schichtsystemen

Gegenstand der Dissertation ist die Fluoreszenz von organischen Farbstoffmolekülen, die in oder in der Nähe von Schichtsystemen angeordnet sind. Dafür wird mit der Methode der Greenschen Funktion zunächst eine klassisch elektrodynamische Beschreibung der Fluoreszenz eines Emitters im Schichtsystem weiterentwickelt, um das Strahlungsfeld und die Lebensdauer der Fluoreszenzemission zu beschreiben. Diese theoretischen Vorhersagen werden an Ensembles von Farbstoffmolekülen experimentell überprüft. Für die Messung der Fluoreszenzlebensdauer wird eine modifizierte Box-Car-Methode vorgestellt, welche die korrekte Lebensdauermessung unabhängig von Bleicheffekten gestattet. Es wird demonstriert, dass die Parameter der optischen Anregungs- und Nachweissysteme das experimentell beobachtete zeitliche Verhalten der Fluoreszenz molekularer Ensembles in einem Schichtsystem beeinflussen

Cavitation bubble wall pressure measurement by an electromagnetic surface wave enhanced pump-probe configuration

We report on the measurement of the pressure associated with a shock wave within a very thin layer (100 nm) in proximity of a boundarysurface. In the experiments, the shock wave was emitted by a cavitation bubble generated by a pulsed pump laser in water. We developed apump-probe setup based on the detection of the light scattered at the surface of a one-dimensional photonic crystal, which was purposelydesigned to sustain a surface electromagnetic wave in the visible range and to enhance the optical response. In order to better understand thephenomenon, we implemented numerical simulations to describe the light scattering intensity distributions through a modified Rayleigh’smethod. We report, with a LoD of about 0.1 MPa, the measurements of the pressure at a surface in the presence of a laser-induced cavitationbubble generated at different distances from the surface and for different pulse energies

Design rules for combined label-free and fluorescence Bloch surface wave biosensors

We report on the fabrication and physical characterization of optical biosensors implementing simultaneous label-free and fluorescence detection and taking advantage of the excitation of Bloch surface waves at a photonic crystal’s truncation interface. Two types of purposely-designed one dimensional photonic crystals on molded organic substrates with micro-optics were fabricated. These feature either high or low finesse of the Bloch surface wave resonances and were tested on the same optical readout system. The experimental results show that designing biochips with a large resonance quality factor does not necessarily lead in the real case to an improvement of the biosensor performance. Conditions for optimal biochips’ design and operation of the complete bio-sensing platform are established

Spectral analysis of organic LED emitters’ orientation in thin layers by resonant emission on dielectric stacks

Purposely tailored thin film stacks sustaining surface waves have been utilized to create a unique link between emission angle and wavelength of fluorescent dye molecules. The knowledge of the thin film stack’s properties allows us to derive the intrinsically emitted luminescence spectrum as well as to gain information about the orientation of fluorophores from angularly resolved experiments. This corresponds to replacing all the equipment necessary for polarized spectroscopy with a single smart thin film stack, potentially enabling single shot analyses in the future. The experimental results agree well with those from other established techniques, when analyzing the Rubrene derivative in a 2,4,6-tris(biphenyl-3-yl)-1,3,5-triazine (T2T) host used for the fabrication of optimized organic light-emitting diodes. The findings illustrate how resonant layered stacks can be applied to integrated spectroscopic analyses

Automated substance testing for lab-on-chip devices : From 23rd European Society for Animal Cell Technology (ESACT) Meeting: Better Cells for Better Health Lille, France. 23-26 June 2013

First published by BioMed Central: Kloke, Lutz ; Schimek, Katharina ; Brincker, Sven ; Lorenz, Alexandra ; Jänicke, Annika ; Drewell, Christopher ; Hoffmann, Silke ; Busek, Mathias ; Sonntag, Frank ; Danz, Norbert ; Polk, Christoph ; Schmieder, Florian ; Borchanikov, Alexey ; Artyushenko, Viacheslav ; Baudisch, Frank ; Bürger, Mario ; Horland, Reyk ; Lauster, Roland ; Marx, Uwe : Automated substance testing for lab-on-chip devices : From 23rd European Society for Animal Cell Technology (ESACT) Meeting: Better Cells for Better Health Lille, France. 23-26 June 2013. - In: BMC Proceedings. - ISSN 1753-6561 (online). - 7 (2013), suppl. 6, P28. - doi:10.1186/1753-6561-7-S6-P28

Определение природных и техногенных радионуклидов в бальнеологических объектах

Quantitative detection of angiogenic biomarkers provides a powerful tool to diagnose cancers in early stages and to follow its progression during therapy. Conventional tests require trained personnel, dedicated laboratory equipment and are generally time-consuming. Herein, we propose our developed biosensing platform as a useful tool for a rapid determination of Angiopoietin-2 biomarker directly from patient plasma within 30 minutes, without any sample preparation or dilution. Bloch surface waves supported by one dimensional photonic crystal are exploited to enhance and redirect the fluorescence arising from a sandwich immunoassay that involves Angiopoietin-2. The sensing units consist of disposable and low-cost plastic biochips coated with the photonic crystal. The biosensing platform is demonstrated to detect Angiopoietin-2 in plasma samples at the clinically relevant concentration of 6 ng/mL, with an estimated limit of detection of approximately 1 ng/mL. This is the first Bloch surface wave based assay capable of detecting relevant concentrations of an angiogenic factor in plasma samples. The results obtained by the developed biosensing platform are in close agreement with enzyme-linked immunosorbent assays, demonstrating a good accuracy, and their repeatability showed acceptable relative variations

Biografieforschung: theoretische Perspektiven und methodologische Konzepte für eine re-konstruktive Geschlechterforschung

Die Biografieforschung bezeichnet einen komplexen Forschungsansatz, der auf eine lange Geschichte des wissenschaftlichen Interesses an "persönlichen Dokumenten" verweisen kann. Sie ist eine voraussetzungsvolle Forschungsperspektive, die sich in zentralen Aspekten ihres Vorgehens auf Biografien als theoretisches Konzept, als historisch-empirischen Gegenstand und als komplexe methodologische Strategie bezieht. Andere Begriffe, welche oftmals synonym gebraucht, in der Biografieforschung aber systematisch unterschieden werden, sind "Lebensgeschichte" und "Lebenslauf". Die Autorin skizziert die Perspektiven einer rekonstruktiven Geschlechterforschung innerhalb der Biografieforschung, wozu sie auf die Differenzierungen empirischer Forschung, die methodologischen Prinzipien sowie auf Datenerhebung und Datenanalyse eingeht. Sie hebt insbesondere drei Kontextrelationen bei der Interpretation eines biografischen Textes hervor: Biografie, Interaktion, kulturelle Muster und soziale Regeln. Das skizzierte Konzept von Biografieforschung begreift sie als ein offenes Programm, das vielfältige Anknüpfungspunkte zu aktuellen theoretischen Diskussionen in der Geschlechterforschung aufweist. (ICI2