Nanoparticle Chemistry

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We have developed highly magnetic carbon coated metal nanoparticles that can act as semi-heterogeneous support for protecting groups, reagents, transition metal complexes or organocatalysts. Compounds covalently attached to the graphene coating are amenable to rapid separation from the reaction mixture with the aid of an external magnet.

 

Stable Dispersions of Functionalizable Cobalt Nanoparticles

Contact: Dr. Martin Zeltner

In biological and bio-medical applications target molecules can be detected by magnetically based methods. Requirements that nano-sized magnetic particles need to fulfill include dispersability in aqueous solutions, minimization of unspecific binding, high magnetic properties and an efficient method for the attachment of target molecules to the surface. We therefore work on a nano-sized material on the basis of carbon coated cobalt nanoparticles from which a highly charged polymer is covalently grafted by SI-ATRP to obtain dispersion stability and enhanced antifouling properties. By subsequent post-modification we can functionalize the particles with a covalently bound linker to which several target molecules could be coupled.

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Magnetic Superbasic Proton Sponges

Contact: Dr. Elia Schneider

Work-up in organic synthesis can be very time consuming, particularly when using reagents of solubility similar to the desired products and a low tendency to crystallize. In this respect, organic bases would strongly profit from a tremendously simplified separation.

Therefore, we synthesized a derivative of the superbasic proton sponge 1,8-bis(dimethylamino)naphthalene (DMAN) and covalently linked it to the strongest currently available nanomagnets based on carbon-coated cobalt metal nanoparticles. Using a hexamethylene diisocyanate-linker yielded a base loading of up to 0.10 ± 0.02 mMol g-1. The immobilized magnetic superbase reagent was tested in Knoevenagel and Claisen-Schmidt type condensations and showed conversions up to 99%. Recycling of the catalyst was simple and fast with insignificant decrease in catalytic activity.

Publications in the area:

  • J. Org. Chem., 2014. Link

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Magnetic Enzymes

Contact: Vladimir Zlateski

In the pursuit of robust and reusable biocatalysts nanobiotechnology is currently taking a significant part. Various nano-composites, including magnetic nanoparticles, are attracting more and more attention as immobilization supports. The very high magnetization of the in-house synthesized carbon-coated cobalt nano-magnets allows for a very fast separation on large (15 L) scale making it one step closer to industry. The carbon surface gives a possibility for reliable functionalization and stable covalent attachment of a number of enzymes for applications in biotechnology, chemistry and medicine

Publications in the area:

  • Bioconjugate Chem., 2014. Link

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Magnetic Nanoparticles to Enhance and Target Nucleic Acid Delivery

Contact: Prof. Robert Grass

Magnetofection is a transfection method in which nucleic acids are associated with magnetic particles and delivered into cells by the application of a magnetic field gradient. The magnetic forces concentrate the vectors onto the cells, allowing to obtain high efficiency of transfection with lower incubation time and vector doses in comparison to other methods. Additionally, it permits to magnetically target nucleic acids to specific location, to achieve localized transfection. The method is suitable for both in vitro and in vivo gene delivery. We are currently investigating the full potential of the technique by developing novel, optimal magnetic nanoparticles.

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Wed Jul 26 04:36:54 CEST 2017
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