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End date: 2019 × Start date: 2010 × DDC: 540 × Version: publishedVersion × Publisher: London : RSC Publishing × Subject: Nanoparticles ×

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Now showing 1 - 3 of 3
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    Biofunctionalized zinc peroxide (ZnO2) nanoparticles as active oxygen sources and antibacterial agents
    (London : RSC Publishing, 2017) Bergs, Christian; Brück, Lisa; Rosencrantz, Ruben R.; Conrads, Georg; Elling, Lothar; Pich, Andrij
    Oxygen is one of the most important substances for physiological reactions and metabolisms in biological systems. Through the tailored design of oxygen-releasing materials it might be possible to control different biological processes. In this work we synthesized for the first time zinc peroxide nanoparticles with controlled sizes and biofunctionalized surfaces using a one-step reaction procedure. The zinc peroxide nanoparticles were obtained with tunable sizes (between 4.0 ± 1.2 nm and 9.4 ± 5.2 nm) and were decorated with glucose 1-phosphate (Glc-1P). The specific interaction of the phosphate function of Glc-1P with the nanoparticle surface was monitored by solid state 31P-NMR and zeta-potential measurements. Furthermore, using fluorescence measurements we demonstrated that anchored glucose molecules on the nanoparticle surface are accessible for specific interactions with lectins. It could be shown that these interactions strongly depend on the amount of Glc-1P attached to the nanoparticle surface. Additionally it was demonstrated that the oxygen release from biofunctionalized zinc peroxide nanoparticles could be tuned according to the chemical composition of the nanoparticles and the pH of the aqueous solution. The antibacterial efficiency of the synthesized nanoparticles against Enterococcus faecalis, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia was evaluated by determination of minimal bactericidal concentration (MIC).
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    SPION@polydehydroalanine hybrid particles
    (London : RSC Publishing, 2015) von der Lühe, Moritz; Günther, Ulrike; Weidner, Andreas; Gräfe, Christine; Clement, Joachim H.; Dutz, Silvio; Schacher, Felix H.
    It is generally accepted that a protein corona is rapidly formed upon exposure of nanoparticles to biological fluids and that both the amount and the composition of adsorbed proteins affect the dispersion properties of the resulting particles. Hereby, the net charge and overall charge density of the pristine nanoparticles are supposed to play a crucial role. In an attempt to control both charge and charge distribution, we report on the coating of superparamagnetic iron oxide nanoparticles (SPIONs) with different polyelectrolytes. Starting from orthogonally protected polydehydroalanine, the material can be easily transformed into a polyanion (poly(tert-butoxycarbonyl acrylic acid), PtBAA), polycation (poly(aminomethylacrylate), PAMA), or even a polyzwitterion (polydehydroalanine, PDha). While coating of SPIONs with PtBAA and PDha was shown to be successful, approaches using PAMA have failed so far. The dispersion properties of the resulting hybrid particles have been investigated using dynamic light scattering (DLS), zeta-potential, and TEM measurements – the amount of adsorbed polymer was quantified using vibrating sample magnetometry (VSM) and thermogravimetric analysis (TGA).
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    Construction of cost-effective bimetallic nanoparticles on titanium carbides as a superb catalyst for promoting hydrolysis of ammonia borane
    (London : RSC Publishing, 2018) Guo, Zhangwei; Liu, Tong; Wang, Qingtao; Gao, Guanhui
    Bimetallic cost-effective CoNi nanoparticles (NPs) are conveniently supported on titanium carbides (MXene) by a simple one-step wet-chemical method. The synthesized CoNi/MXene catalysts are characterized by XPS, TEM, STEM-HAADF and ICP-AES. The as-prepared CoNi NPs with a size of 2.8 nm are well dispersed on the MXene surface. It is found that among the CoNi bimetallic system, Co0.7Ni0.3 shows the best performance toward catalyzing ammonia borane (AB) decomposition with a turnover frequency value of 87.6 molH2 molcat−1 min−1 at 50 °C. The remarkable catalytic performance is attributed to the mild affiliation of MXene to NPs, which not only stabilizes NPs to maintain a good dispersion but also leaves sufficient surface active sites to facilitate the catalytic reaction.