Nanophotonics and Single Molecules
Single emitting molecules are currently providing a new window into nanoscale systems ranging from biology to materials science. The amount of information that can be extracted from each single molecule depends upon the specific photophysical properties of the fluorophore and how these properties are affected by the nearby environment. For this reason, it is necessary to develop single-molecule emitters with as many different reporter functions as possible. The first part of this chapter describes a relatively new class of single-molecule fluorophores which offer tunable photophysical properties and, in turn, improved local reporting functionality on the nanometer length scale. The second part of this chapter presents metallic nanostructures which can address a second issue: the mismatch between the typical size of a single fluorophore (~1 nm along a long dimension) and the wavelength of light (~500 nm). Such nanostructures could lead to more efficient excitation of single molecules, in particular, higher excitation probability as well as reduced backgrounds, and effectively higher spatial resolution. Metallic nanostructures based on two triangles formed into a bowtie shape feature large enhancements of the local electromagnetic field and give rise to strong surface-enhanced Raman scattering of molecules. In future work, enhanced electromagnetic structures can be combined with single-molecule reporters in a variety of applications.
Unable to display preview. Download preview PDF.
- Fromm, D.P., A. Sundaramurthy, et al. (2006). Exploring the chemical enhancement for surface-enhanced Raman scattering with Au bowtie nanoantennas. J. Chem. Phys. Commun. 124(6): 061101.Google Scholar
- Kuzyk, M.G. and C.W. Dirk (1998). Characterization Techniques and Tabulations for Organic Nonlinear Optical Materials. New York: Dekker-CRC Press.Google Scholar
- Lakowicz, J.R. (1999). Principles of Fluorescence Spectroscopy. New York: Kluwer Academic.Google Scholar
- Lord, S.J., Z. Lu, et al. (2007). Photophysical properties of acene DCDHF fluorophores: Long-wavelength single-molecule emitters designed for cellular imaging. J. Phys. Chem. A published on Web 8/24/2007, “http://dx.doi.org/10.1021/jp0712598” 10.1021/jp0712598.
- Nalwa, H.S. and S. Miyata (Eds.) (1997). Nonlinear Optics of Organic Molecules and Polymers. Boca Raton, FL: CRC Press.Google Scholar
- Nicoud, J.F. and R.J. Twieg (1987). Design and Synthesis of Organic Molecular Compounds for Efficient Second Harmonic Generation. Nonlinear Optical Properties of Organic Molecules and Crystals. D. S. Chemla and J. Zyss. New York: Academic Press. 1: 227–296.Google Scholar
- Palik, E.D. (1985). Handbook of Optical Constants. Orlando, FL: Academic Press.Google Scholar
- Prasad, P.N. and D.J. Williams (1991). Introduction to Nonlinear Optical Effects in Molecules and Polymers. New York: John Wiley.Google Scholar
- Tsien, R.Y. and A. Waggoner (1995). Fluorophores for confocal microscopy. Handbook of Biological Confocal Microscopy 2nd ed. J.B. Pawley. New York: Plenum Press, 267–279.Google Scholar
- Wang, Z., Rothberg, L.J. (2005). Origins of blinking in single-molecule raman spectroscopy. J Chem Phys B: jp0460947.Google Scholar
- Zyss, J., Ed. (1994). Molecular Nonlinear Optics. New York: Academic Press.Google Scholar