Electrophoretic Separation of Nanoparticles with a Discrete Number of Functional Groups

Authors

  • R. A. Sperling,

    1. Center for Nanoscience, Ludwig-Maximilians-Universität München, Amalienstr. 54, 80799 Munich, Germany
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  • T. Pellegrino,

    1. Center for Nanoscience, Ludwig-Maximilians-Universität München, Amalienstr. 54, 80799 Munich, Germany
    2. INFM-NNL, National Nanotechnology Laboratory, Distretto Tecnologico ISUFI Via Arnesano, 73100 Lecce, Italy
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  • J. K. Li,

    1. Center for Nanoscience, Ludwig-Maximilians-Universität München, Amalienstr. 54, 80799 Munich, Germany
    2. Center for Nano Bioengineering and R&D Center for Membrane Technology, Chung-Yuan Christian University, No. 200, Chungbei Rd., Chung Li 32023, Taiwan
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  • W. H. Chang,

    1. Center for Nano Bioengineering and R&D Center for Membrane Technology, Chung-Yuan Christian University, No. 200, Chungbei Rd., Chung Li 32023, Taiwan
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  • W. J. Parak

    1. Center for Nanoscience, Ludwig-Maximilians-Universität München, Amalienstr. 54, 80799 Munich, Germany
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  • This work was supported in part by the Deutsche Forschungsgemeinschaft (DFG, Emmy Noether Grant), and the European Union (SA-NANO STREP project). The CdSe/ZnS particles used in this study were prepared by courtesy of Stefan Kudera. The authors are grateful to Dr. Liberato Manna and Prof. Dr. Hermann Gaub for helpful discussions. Supporting Information is available online from Wiley InterScience or from the author.

Abstract

A concept is describe that facilitates the modification of colloidal nanoparticles of different materials with an exactly known number of variable functional groups. In particular, a procedure for the surface functionalization of nanoparticles with a controlled number of mono- or bifunctional poly(ethylene glycol) (PEG) molecules of suitable chain length is reported. Conjugates of nanoparticles with one, two, and three PEG molecules per nanoparticle could be separated using gel electrophoresis. Molecules with additional functionalities could be conjugated to the free ends of the bifunctional PEG molecules. In this way the PEG molecules act as convenient spacers that allow for the sorting of nanoparticles with a discrete number of functional groups.

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