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    Complex Metal Nanostructures with Programmable Shapes from Simple DNA Building Blocks
    (Weinheim : Wiley-VCH, 2021) Ye, Jingjing; Aftenieva, Olha; Bayrak, Türkan; Jain, Archa; König, Tobias A.F.; Erbe, Artur; Seidel, Ralf
    Advances in DNA nanotechnology allow the design and fabrication of highly complex DNA structures, uisng specific programmable interactions between smaller nucleic acid building blocks. To convey this concept to the fabrication of metallic nanoparticles, an assembly platform is developed based on a few basic DNA structures that can serve as molds. Programming specific interactions between these elements allows the assembly of mold superstructures with a range of different geometries. Subsequent seeded growth of gold within the mold cavities enables the synthesis of complex metal structures including tightly DNA-caged particles, rolling-pin- and dumbbell-shaped particles, as well as T-shaped and loop particles with high continuity. The method further supports the formation of higher-order assemblies of the obtained metal geometries. Based on electrical and optical characterizations, it is expected that the developed platform is a valuable tool for a self-assembly-based fabrication of nanoelectronic and nanooptic devices. © 2021 The Authors. Advanced Materials published by Wiley-VCH GmbH
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    Enzymatic Catalysis at Nanoscale: Enzyme-Coated Nanoparticles as Colloidal Biocatalysts for Polymerization Reactions
    (Washington, DC : ACS Publications, 2017) Kreuzer, Lucas Philipp; Männel, Max Julius; Schubert, Jonas; Höller, Roland P. M.; Chanana, Munish
    Enzyme-catalyzed controlled radical polymerization represents a powerful approach for the polymerization of a wide variety of water-soluble monomers. However, in such an enzyme-based polymerization system, the macromolecular catalyst (i.e., enzyme) has to be separated from the polymer product. Here, we present a compelling approach for the separation of the two macromolecular species, by taking the catalyst out of the molecular domain and locating it in the colloidal domain, ensuring quasi-homogeneous catalysis as well as easy separation of precious biocatalysts. We report on gold nanoparticles coated with horseradish peroxidase that can catalyze the polymerization of various monomers (e.g., N-isopropylacrylamide), yielding thermoresponsive polymers. Strikingly, these biocatalyst-coated nanoparticles can be recovered completely and reused in more than three independent polymerization cycles, without significant loss of their catalytic activity.