8 research outputs found
Assessing Polymer-Surface Adhesion with a Polymer Collection
Polymer modification plays an important role in the construction of devices, but the lack of fundamental understanding on polymer-surface adhesion limits the development of miniaturized devices. In this work, a thermoplastic polymer collection was established using the combinatorial laser-induced forward transfer technique as a research platform, to assess the adhesion of polymers to substrates of different wettability. Furthermore, it also revealed the influence of adhesion on dewetting phenomena during the laser transfer and relaxation process, resulting in polymer spots of various morphologies. This gives a general insight into polymer-surface adhesion and connects it with the generation of defined polymer microstructures, which can be a valuable reference for the rational use of polymers
OnâChip NeoâGlycopeptide Synthesis for Multivalent Glycan Presentation
Single glycanâprotein interactions are often weak, such that glycan binding partners commonly utilize multiple, spatially defined binding sites to enhance binding avidity and specificity. Current array technologies usually neglect defined multivalent display. Laserâbased array synthesis technology allows for flexible and rapid onâsurface synthesis of different peptides. By combining this technique with click chemistry, neoâglycopeptides were produced directly on a functionalized glass slide in the microarray format. Density and spatial distribution of carbohydrates can be tuned, resulting in wellâdefined glycan structures for multivalent display. The two lectins concanavalin A and langerin were probed with different glycans on multivalent scaffolds, revealing strong spacingâ, densityâ, and ligandâdependent binding. In addition, we could also measure the surface dissociation constant. This approach allows for a rapid generation, screening, and optimization of a multitude of multivalent scaffolds for glycan binding
Probing Multivalent Carbohydrate-Protein Interactions With On-Chip Synthesized Glycopeptides Using Different Functionalized Surfaces
Multivalent ligandâprotein interactions are a commonly employed approach by nature in many biological processes. Single glycanâprotein interactions are often weak, but their affinity and specificity can be drastically enhanced by engaging multiple binding sites. Microarray technology allows for quick, parallel screening of such interactions. Yet, current glycan microarray methodologies usually neglect defined multivalent presentation. Our laser-based array technology allows for a flexible, cost-efficient, and rapid in situ chemical synthesis of peptide scaffolds directly on functionalized glass slides. Using copper(I)-catalyzed azideâalkyne cycloaddition, different monomer sugar azides were attached to the scaffolds, resulting in spatially defined multivalent glycopeptides on the solid support. Studying their interaction with several different lectins showed that not only the spatially defined sugar presentation, but also the surface functionalization and wettability, as well as accessibility and flexibility, play an essential role in such interactions. Therefore, different commercially available functionalized glass slides were equipped with a polyethylene glycol (PEG) linker to demonstrate its effect on glycanâlectin interactions. Moreover, different monomer sugar azides with and without an additional PEG-spacer were attached to the peptide scaffold to increase flexibility and thereby improve binding affinity. A variety of fluorescently labeled lectins were probed, indicating that different lectinâglycan pairs require different surface functionalization and spacers for enhanced binding. This approach allows for rapid screening and evaluation of spacing-, density-, ligand and surface-dependent parameters, to find optimal lectin binders.BMBF, 13XP5050A, Erforschung einer neuen Methode fĂŒr die Herstellung von hochdichten MolekĂŒlbibliotheken (cLIFT
Laser-driven growth of structurally defined transition metal oxide nanocrystals on carbon nitride photoelectrodes in milliseconds
Fabrication of hybrid photoelectrodes on a subsecond timescale with low energy consumption and possessing high photocurrent densities remains a centerpiece for successful implementation of photoelectrocatalytic synthesis of fuels and value-added chemicals. Here, we introduce a laser-driven technology to print sensitizers with desired morphologies and layer thickness onto different substrates, such as glass, carbon, or carbon nitride (CN). The specially designed process uses a thin polymer reactor impregnated with transition metal salts, confining the growth of transition metal oxide (TMO) nanostructures on the interface in milliseconds, while their morphology can be tuned by the laser. Multiple nano-p-n junctions at the interface increase the electron/hole lifetime by efficient charge trapping. A hybrid copper oxide/CN photoanode with optimal architecture reaches 10 times higher photocurrents than the pristine CN photoanode. This technology provides a modular approach to build a library of TMO-based composite films, enabling the creation of materials for diverse applications
On-Chip Neo-Glycopeptide Synthesis for Multivalent Glycan Presentation
Single glycan-protein interactions are often weak, such that glycan binding partners commonly utilize multiple, spatially defined binding sites to enhance binding avidity and specificity. Current array technologies usually neglect defined multivalent display. Laser-based array synthesis technology allows for flexible and rapid on-surface synthesis of different peptides. By combining this technique with click chemistry, neo-glycopeptides were produced directly on a functionalized glass slide in the microarray format. Density and spatial distribution of carbohydrates can be tuned, resulting in well-defined glycan structures for multivalent display. The two lectins concanavalin A and langerin were probed with different glycans on multivalent scaffolds, revealing strong spacing-, density-, and ligand-dependent binding. In addition, we could also measure the surface dissociation constant. This approach allows for a rapid generation, screening, and optimization of a multitude of multivalent scaffolds for glycan binding
OnâChip NeoâGlycopeptide Synthesis for Multivalent Glycan Presentation
Single glycan-protein interactions are often weak, such that glycan binding partners commonly utilize multiple, spatially defined binding sites to enhance binding avidity and specificity. Current array technologies usually neglect defined multivalent display. Laser-based array synthesis technology allows for flexible and rapid on-surface synthesis of different peptides. Combining this technique with click chemistry, we produced neo-glycopeptides directly on a functionalized glass slide in the microarray format. Density and spatial distribution of carbohydrates can be tuned, resulting in well-defined glycan structures for multivalent display. We probed the two lectins concanavalin A and langerin with different glycans on multivalent scaffolds, revealing strong spacing-, density-, and ligand-dependent binding. In addition, we could also measure the surface dissociation constant. This approach allows for a rapid generation, screening, and optimization of a multitude of multivalent scaffolds for glycan binding
Cover Feature: OnâChip NeoâGlycopeptide Synthesis for Multivalent Glycan Presentation (Chem. Eur. J. 44/2020)
Self-Assembly of Ultralong Aligned Dipeptide Single Crystals
Oriented arrangement
of single crystals plays a key role in improving
the performance of their functional devices. Herein we describe a
method for the exceptionally fast fabrication (mm/min) of ultralong
aligned dipeptide single crystals (several centimeters). It combines
an induced nucleation step with a continuous withdrawal of substrate,
leading to specific evaporation/composition conditions at a three-phase
contact line, which makes the growth process controllable. These aligned
dipeptide fibers possess a uniform cross section with active optical
waveguiding properties that can be used as waveguiding materials.
The approach provides guidance for the controlled arrangement of organic
single crystals, a family of materials with considerable potential
applications in large-scale functional devices