- About Us
- Career Center
- Nano-Social Network
- Nano Consulting
- My Account
Oct 27, 2008
Refreshments will be served.
City College of New York, 160 Convent Avenue, Steinman Hall, Rm. 312
phone (212) 650-7232
Professor Nicholas Kotov, from the University of Michigan, speaks on the topic of: Self-Assembled Systems of Nanoparticles: Surprising Analogies with Proteins and New Optical Properties.
Figure 1: (A) Schematics of the system of CdTe NWs and Au NPs with plasmon-exciton interactions. (B) Calculated geometry of self-organized CdTe sheets with hexagonal packing. closely matching the experiment. A B Surface chemistries of nanoparticles and proteins reveal a lot of similarities which can also be traced in chemical and biological behavior starting from processing techniques to cell signaling. In this presentation they will be reviewed and compared. Special attention will be given self-organization phenomena taking place with semiconductor nanocolloids starting with supercrystals from nearly spherical nanoparticles and nanoparticle bioconjugates to 1D and 2D assemblies. Comparison of the processes in solution of CdTe and other nanocolloids reveals a number of surprising similarities with processes in proteins. The conclusion that will be reached that this is the result of fundamental analogy in the scales between proteins and nanoparticles. This conclusion will be substantiated by a variety of experimental and theoretical observations of analogies between biological effects of nanoparticles and proteins. In essence, the talk will show that anisotropic forces arising between nanocrystalline particles drive the self-assembly behavior of these colloidal particles. Interaction anisotropy between CdTe nanoparticles in solution leads to their spontaneous, template-free organization into free-floating sheets. Electrostatic interactions arising from a dipole moment and a small positive charge combined with directional hydrophobic attraction between the nanoparticles are the driving forces for the self-assembly, which we demonstrate by computer simulation. The laws governing this process show conceptual similarities with assembly of proteins. Electronic interactions in nanoparticle assemblies represent one of the fundamental problems of nanotechnology. Excitons and plasmons are the two most typical excited states of nanostructures, which were shown to produce coupled electronic systems. The concept of these interactions between the Au and CdTe nanoparticles and nanowires will be discussed in terms of quantum mechanical coupling of excited states and unusual optical effects. As such, in presence of dynamic component for excitons theory predicts that emission of coupled excitations in nanowires with variable electronic confinement is stronger, shorter, and blue-shifted. These predictions were confirmed with high degree of accuracy in molecular spring assemblies, where one can reversibly change the distance between the exciton and plasmon. The prepared systems were made protein-sensitive by incorporating antibodies in molecular springs. Modulation of exciton-plasmon interactions can serve as wavelength-based biodetection tool, which can resolve difficulties of quantification of luminescence intensity for complex media and optical pathways. Relevant References. Z. Tang, N. A. Kotov, M. Giersig, Science 2002, 297, 237-240. Tang, Z. Zhang, Z.; Wang Y.; Glotzer, S. C. Kotov, N. A., Science, 2006, 314 (5797) 274-278. Sinyagin, A. Belov, A. Tang, Z. Kotov. N. A. J. Phys. Chem. B 2006, 110(14), 7500-7507 J. Lee, A. O. Govorov, N. A. Kotov, Angew. Chem. Intern. Ed. 2005, 44, 7439-7442. J. Lee, A. O. Govorov, J. Dulka, N. A. Kotov, Nano Lett. 2004, 4, 2323-2330. J. Lee, A. O. Govorov, N. A. Kotov, Nature Materials. 2007, 6(4), 291-295.
Refreshments will be served.
Founded in 1817, the New York Academy of Sciences is an independent, nonprofit organization with more than 25,000 members in 140 countries. The Academy fulfills its mission through the following efforts:
The Conferences Program sponsors 8-12 major events annually, bringing together international groups of speakers to exchange information on basic or applied frontier research fields and on the broader societal roles of science and technology.
The Frontiers of Science Program convenes senior investigators and young scientists regularly in multi-speaker, interdisciplinary discussion groups to explore ideas and exchange information in the biological, chemical, and computational sciences.
The Physical Sciences & Engineering Program provides a forum for the exchange of new ideas and data in interdisciplinary areas such as machine learning, green science and sustainability, quantitative finance, string theory, and astrophysics and cosmology.
The Science Alliance for Graduate Students and Postdocs is a collaboration among 30 universities and other scientific institutions in the United States and around the world that provides guidance on careers, networking, and mentoring for 5000 young investigators.
Scientists Without BordersSM mobilizes and coordinates science-based efforts in the developing world to improve health care, foster agricultural progress, promote environmental well-being, and devise energy solutions.
The Committee on the Human Rights of Scientists fights on behalf of scientists, health professionals, engineers, and educators who have been detained, imprisoned, exiled, or deprived of the right to pursue science.
The Academy's International Programs include partnerships with the major universities in the United Kingdom and the Chinese Ministry of Health, and programs in the United Arab Emirates and Mexico City.
For more information, please click here
Copyright © NYAS.orgIf you have a comment, please Contact us.
Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
|Related News Press|
News and information
Graphene makes rubber more rubbery May 23rd, 2016
Searching for a nanotech self-organizing principle May 1st, 2016
Brookhaven's Oleg Gang Named a Battelle 'Inventor of the Year': Recognized for work using DNA to guide and regulate the self-assembly of nanoparticles into clusters and arrays with controllable properties April 25th, 2016
Novel gene therapy shows potential for lung repair in asthma May 18th, 2016
Nanometrics Announces Upcoming Investor Events May 10th, 2016