Sens-o-Spheres – Mobile, miniaturisierte Sensorplattform für die ortsungebundene Prozessmessung in wässrigen Lösungen

Zur Prozessmessung in Flüssigkeiten wird ein Konzept vorgestellt, das mittels miniaturisierter Sensorkugeln eine ortsveränderliche Aufnahme von Prozessmesssignalen – z. B. der Temperatur – ermöglicht und diese kontinuierlich aus dem Reaktionsvolumen an eine Basisstation überträgt. Das System beinhaltet nicht nur die Miniaturisierung der Messstelle auf einen Kugeldurchmesser von 7,8 mm sondern auch die Abstimmung der Gesamtdichte auf die Prozessbedingungen, um eine gleichmäßige Verteilung der Messpunkte auf das gesamte Reaktionsvolumen zu ermöglichen. Für die Verwendung im Bioprozess wurde eine bio-inerte Kapselung für die gesamte Messelektronik entwickelt und die Funktionstüchtigkeit in mehreren Bioreaktorsystemen demonstriert. Das Messsystem wird mit einer induktiv wieder aufladbaren Energiequelle betrieben und hat eine Reichweite von mehr als 30 cm durch die Flüssigkeitssäule

Weak Glycolipid Binding of a Microdomain-Tracer Peptide Correlates with Aggregation and Slow Diffusion on Cell Membranes

10.1371/journal.pone.0051222PLoS ONE712

Multiple activation of ion track etched polycarbonate for the electroless synthesis of metal nanotubes

In our study, we examined the formation of thin films of silver nanoparticles on polycarbonate and the influence of the silver loading on the electroless synthesis of metal nanotubes. Control of the silver film thickness occurred by consecutive dipping of the polymer template in tin(II) and silver(I) solutions. The deposition progress was studied using UV-Vis spectroscopy. The reaction mechanism relies on the adsorption of reactive ions on the polymer template as well as on the silver nanoparticles. The initial catalytic activity of silver-covered ion track etched polycarbonate is an important governing factor for the electroless synthesis of metal nanotubes with desired thickness and shape. Therefore, the presented method allows specific template preparation according to given synthetic demands. High aspect ratio copper, gold, and platinum nanotubes were produced by the combination of sufficiently activated templates with optimized electroless plating procedures

Reactions of Secondary Amines with Bis(η⁵:η¹‑pentafulvene)titanium Complexes: Formation of Titanium Amides and Titanaaziridines

The reactions of bis­(η⁵:η¹-pentafulvene)­titanium complexes (<b>1</b>) with 19 different secondary amines (<b>Aa</b>–<b>s</b>) have been investigated. Depending on the substitution pattern of <b>1</b> and nature of the amine used, different reaction products are formed. With use of bis­(η⁵:η¹-di­(<i>p</i>-tolyl)­pentafulvene)titanium (<b>1b</b>) and <i>N</i>-methylanilines (<b>Aa</b>,<b>b</b>), <i>N</i>-methylbenzylamines (<b>Ac</b>,<b>d</b>), <i>N</i>-methylcyclohexylamine (<b>Ae</b>), and dibenzylamine (<b>Af</b>), titanium monoamides of the type (η⁵-C₅H₄CH­(<i>p</i>-tolyl)₂)­(η⁵:η¹-C₅H₄C­(<i>p</i>-tolyl)₂TiNR₂ (<b>2a</b>–<b>f</b>) have been isolated in high yields and characterized, including by single-crystal X-ray diffraction. By the reactions of bis­(η⁵:η¹-adamantylidene)­titanium (<b>1a</b>) and <b>Af</b>, diethylamine (<b>Ag</b>), and 2-methylpiperidine (<b>Ah</b>) similar monoamides <b>3f</b>–<b>h</b> are formed. The formation of titanium bis-amides employing different types of secondary amines (<b>Aa</b>–<b>s</b>) is not observed. The formation of titanaaziridines is observed exclusively by using <b>1a</b> and <i>N</i>-methylanilines (<b>Aa</b>,<b>b</b>), <i>N</i>-benzylphenylamine (<b>Ai</b>), and <i>N</i>-benzyltrimethylsilylamines (<b>Aj</b>,<b>k</b>). The titanaaziridine <b>4i</b> undergoes a regioselective ring enlargement reaction with 1-hexyne. By the reaction of <b>4i</b> and phenylacetylene a ring opening with formation of (Cp^Ad)₂Ti­(NPh­(CH₂Ph)­CCPh) (<b>6</b>) is observed. The acetylide <b>6</b> undergoes a thermal decomposition to give the zigzag butadiyne complex <b>7</b>. In addition to the ring enlargement of <b>4j</b> by ketones a ketone insertion in the titanium–Cp bond is found, as proved for <b>8</b> by single-crystal X-ray diffraction

Polycarbonate activation for electroless plating by dimethylaminoborane absorption and subsequent nanoparticle deposition

Electroless plating of metal films on polymer substrates usually requires the presence of metal particles acting as catalytically active nuclei for the deposition reaction. Herein, we present a novel and versatile approach towards the activation of polycarbonate substrates with metal nanoparticles. It is based on the diffusion of dimethylaminoborane into the polymer matrix, followed by reaction of the sensitized substrates with metal salt solutions. The reducing agent uptake was controlled by changing the duration of the sensitization and the dimethylaminoborane concentration in the sensitization solution. Different seed types (Ag, Au, Pd, Pt and Rh) were deposited by variation of the activation solution. The proposed mechanism was confirmed with FTIR and TEM measurements. In addition, AFM revealed that apart from a slight roughening in the nanometer range, the surface morphology of the polymer remained unchanged, rendering the method viable for template-based nanomaterial fabrication. Due to its pronounced variability, the new technique allows to tailor the activity of polymer substrates for consecutive electroless plating. The feasibility and nanoscale homogeneity of the process were proven by the electroless fabrication of well-defined Au and Pt nanotubes in ion-track etched polycarbonate templates. The combination of features (use of simple and easily scalable wet-chemical processes, facile seed variation, high activation quality on complex surfaces) renders the outlined technique promising for the fabrication of intricate nanomaterials as well as for the metallization of macroscopic work pieces

Sens-o-Spheres – Mobile, miniaturisierte Sensorplattform für die ortsungebundene Prozessmessung in wässrigen Lösungen

Zur Prozessmessung in Flüssigkeiten wird ein Konzept vorgestellt, das mittels miniaturisierter Sensorkugeln eine ortsveränderliche Aufnahme von Prozessmesssignalen – z. B. der Temperatur – ermöglicht und diese kontinuierlich aus dem Reaktionsvolumen an eine Basisstation überträgt. Das System beinhaltet nicht nur die Miniaturisierung der Messstelle auf einen Kugeldurchmesser von 7,8 mm sondern auch die Abstimmung der Gesamtdichte auf die Prozessbedingungen, um eine gleichmäßige Verteilung der Messpunkte auf das gesamte Reaktionsvolumen zu ermöglichen. Für die Verwendung im Bioprozess wurde eine bio-inerte Kapselung für die gesamte Messelektronik entwickelt und die Funktionstüchtigkeit in mehreren Bioreaktorsystemen demonstriert. Das Messsystem wird mit einer induktiv wieder aufladbaren Energiequelle betrieben und hat eine Reichweite von mehr als 30 cm durch die Flüssigkeitssäule

LC-ESI-HRMS - lipidomics of phospholipids – characterization of extraction, chromatography and detection parameters

Lipids are a diverse class of molecules involved in many biological functions including cell signaling or cell membrane assembly. Owing to this relevance, LC-MS/MS based lipidomics emerged as a major field in modern analytical chemistry. Here, we thoroughly characterized the influence of MS and LC settings – of a Q Exactive HF operated in Full MS/data-dependent MS2 TOP N acquisition mode - in order to optimize the semi-quantification of polar lipids. Optimization of MS-source settings improved the signal intensity by factor 3 compared to default settings. Polar lipids were separated on an ACQUITY Premier CSH C18 reversed-phase column (100 x 2.1 mm, 1.7 µm, 130 Å) during an elution window of 28 min, leading to a sufficient number of both data points across the chromatographic peaks, as well as MS2 spectra. Analysis was carried out in positive and negative ionization mode enabling the detection of a broader spectrum of lipids and to support the structural characterization of lipids. Optimal sample preparation of biological samples was achieved by liquid-liquid extraction using MeOH/MTBE resulting in an excellent extraction recovery &gt;85% with an intra-day and inter-day variability &lt;15%. The optimized method was applied on the investigation of changes in the phospholipid pattern in plasma from human subjects supplemented with n3-PUFA (20:5 and 22:6). The strongest increase was observed for lipids bearing 20:5, while 22:4 bearing lipids were lowered. Specifically, LPC 20:5_0:0 and PC 16:0_20:5 were found to be strongest elevated, while PE 18:0_22:4 and PC 18:2_18:2 were decreased by n3-PUFA supplementation. These results were confirmed by targeted LC-MS/MS using commercially available phospholipids as standards