INTRACELLULAR CHEMICAL MEASUREMENTS [electronic resource] : A GENERALIZED APPROACH WITH HIGH-SPATIAL RESOLUTION USING FUNCTIONALIZED NANOPARTICLES
- Washington, D.C. : United States. Dept. of Energy, 2007. and Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Physical Description:
- PDF-file: 18 pages; size: 2.1 Mbytes
- Additional Creators:
- Lawrence Berkeley National Laboratory, United States. Department of Energy, and United States. Department of Energy. Office of Scientific and Technical Information
- Restrictions on Access:
- Free-to-read Unrestricted online access
- We are developing an alternative approach to optical probes that will ultimately allow us to measure chemical concentrations in microenvironments within cells and tissues. This approach is based on monitoring the surface-enhanced Raman scattering (SERS) response of functionalized metal nanoparticles (50-100 nm in diameter). SERS allows for the sensitive detection of changes in the state of chemical groups attached to individual nanoparticles and small clusters. We present the development of a nanoscale pH meter. The pH response of these nanoprobes is tested in a cell-free medium, measuring the pH of the solution immediately surrounding the nanoparticles. We developed and used SERS correlation spectroscopy and single particle/cluster SERS spectroscopy to characterize heterogeneities in the SERS signal, which result from the formation of small nanoparticle clusters. These heterogeneities have historically provided inconsistent response to pH, leading a poor sensitivity of ≈1 pH unit. The response of the nanoscale pH meters is tested under a wide range of conditions to approach the complex environment encountered inside living cells and to optimize probe performance. We have also developed a rapid scanning technique to obtain pH information using confocal microscopic imaging. Together with the development of hollow gold nanoshells with collaborators, this project enables future cell-based studies of pH using SERS. This research will be continued as a collaboration with the Center for Biophotonics Science and Technology (CBST) at UC Davis Medical Center.
- Published through SciTech Connect., 03/05/2007., "ucrl-tr-228796", and Laurence, T.
- Funding Information:
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