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There is now a CONTENT FREEZE for Mercury while we switch to a new platform. It began on Friday, March 10 at 6pm and will end on Wednesday, March 15 at noon. No new content can be created during this time, but all material in the system as of the beginning of the freeze will be migrated to the new platform, including users and groups. Functionally the new site is identical to the old one. webteam@gatech.edu
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"Biomimetic Assemblies of Nanoparticles"
Nicholas Kotov, Ph.D.
Departments of Chemical Engineering, Materials Science and Engineering
University of Michigan
Seminar will be made available via videoconference in the Health Sciences Research Building, room E 182 and Technology Enterprise Park, room 104.
Intrinsic ability of nanoparticles (NPs) to self-organize can be seen virtually everywhere around us. Although omnipresent, the mechanisms of these processes are not well understood and include many surprises. A step toward clarification of these mechanisms can be achieved by juxtaposition of self-organization processes known for biological species and NPs. Key results of biomimetic and theoretical analysis based on consideration of electrostatic and dispersion interactions of such processes will be presented. Two general classes of assemblies will be considered. Self-organized structures known as “terminal” cannot grow beyond a certain size. The second class of assemblies known as “extended” may continuously grow along specific directions. The distinction between these two cases will be made based on the balance of attractive and repulsive interactions between NPs using simplified phase diagrams. The key differences with similar assemblies observed for biological building blocks and fundamental problems associated with quantitative description of forces between NPs will be elaborated. Practical relevance of terminal and extended assemblies from NPs is based on their simplicity, versatility, and multifunctionality. They also retain special optical, electrical, and catalytic properties of inorganic nanomaterials. Extended assemblies in the form of nanoparticle sheets can display suprizingly high electron conductivity suitable for electronic and energy harvesting devices. Self-limited supraparticles can be made from a variety of charged NPs as well as from their combinations with biomolecules. Low molecular weight molecules can be easily incorporated into them as well. Terminal assemblies were also made using self-limited biological interactions typical for oligonucleotide strands. Chiral assemblies with geometry of “open scissors” were made from gold nanorods using this approach. They demonstrated exceptionally low detection limits for detection
(LOD) of DNA and proteins when circular dichroism spectroscopy is used for an analytical tool.
Ross Ethier, Ph.D. - faculty host
