Single glycan-protein interactions are often weak, such that glycan binding partnerscommonly utilizemultiple, spatially defined binding sites to enhance binding avidity and specificity.C urrent array technologiesu sually neglect defined multivalent display.L aser-based array synthesis technology allows for flexible and rapid on-surface synthesis of different peptides. By combining this technique with click chemistry,n eo-glycopeptides werep roduced 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.T he two lectins concanavalin Aa nd langerin were probedw ith different glycanso nm ultivalent scaffolds, revealing strong spacing-, density-, and ligand-dependent binding. In addition, we could also measuret he surfaced issociation constant.T his approach allows for ar apid generation, screening, and optimization of am ultitudeo fm ultivalent scaffoldsfor glycan binding.

In this introductory lecture we discuss the state-of-the-art glycan microarray technology, with emphasis on novel approaches to immobilize collections of glycans in a defined, multivalent manner.

A low‐cost laser‐based printing setup is presented, which allows for the spot‐wise patterning of surfaces with defined polymer nanolayers. These nanolayer spots serve as a “solid solvent,” embedding different chemicals, chemical building blocks, materials, or precursors and can be stacked on top of each other. By melting the spot pattern, the polymer‐embedded molecules are released for chemical reaction. This enables researchers to quickly pattern a surface with different molecules and materials, mixing them directly on the surface for high‐throughput chemical synthesis to generate and screen diverse microarray libraries. In contrast to expensive ink‐jet or contact printing, this approach does not require premixing of inks, which enables in situ combinatorial mixing. Easy access and versatility of this patterning approach are shown by generating microarrays of various biomolecules, such as glycans for the first time, to screen interactions of antibodies and lectins. In addition, a layer‐by‐layer solid‐phase synthesis of peptides directly on the microarray is presented. Amino acid–containing nanolayers are repeatedly laser‐transferred and reacted with the functionalized acceptor surface in defined patterns. This simple system enables a reproducible array production, down to spot‐to‐spot distances of 100 µm, and offers a flexible and cheap alternative to expensive spotting robot technology.

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The use of organic materials with reversible redox activity holds enormous potential for next‐generation Li‐ion energy storage devices. Yet, most candidates are not truly sustainable, i.e., not derived from renewable feedstock or made in benign reactions. Here an attempt is reported to resolve this issue by synthesizing an organic cathode material from tannic acid and microporous carbon derived from biomass. All constituents, including the redox‐active material and conductive carbon additive, are made from renewable resources. Using a simple, sustainable fabrication method, a hybrid material is formed. The low cost and ecofriendly material shows outstanding performance with a capacity of 108 mAh g−1 at 0.1 A g−1 and low capacity fading, retaining approximately 80% of the maximum capacity after 90 cycles. With approximately 3.4 V versus Li+/Li, the cells also feature one of the highest reversible redox potentials reported for biomolecular cathodes. Finally, the quinone‐catecholate redox mechanism responsible for the high capacity of tannic acid is confirmed by electrochemical characterization of a model compound similar to tannic acid but without catecholic groups.

Laser‐induced forward transfer (LIFT) is a rapid laser‐patterning technique for high‐throughput combinatorial synthesis directly on glass slides. A lack of automation and precision limits LIFT applications to simple proof‐of‐concept syntheses of fewer than 100 compounds. Here, an automated synthesis instrument is reported that combines laser transfer and robotics for parallel synthesis in a microarray format with up to 10 000 individual reactions cm−2. An optimized pipeline for amide bond formation is the basis for preparing complex peptide microarrays with thousands of different sequences in high yield with high reproducibility. The resulting peptide arrays are of higher quality than commercial peptide arrays. More than 4800 15‐residue peptides resembling the entire Ebola virus proteome on a microarray are synthesized to study the antibody response of an Ebola virus infection survivor. Known and unknown epitopes that serve now as a basis for Ebola diagnostic development are identified. The versatility and precision of the synthesizer is demonstrated by in situ synthesis of fluorescent molecules via Schiff base reaction and multi‐step patterning of precisely definable amounts of fluorophores. This automated laser transfer synthesis approach opens new avenues for high‐throughput chemical synthesis and biological screening.

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Multivalent ligand–protein interactions are a commonly employed approach by nature in many biological processes. Single glycan–protein 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 azide–alkyne 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 glycan–lectin 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 lectin–glycan 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.