Gold nanoparticles enhanced optical properties

Figure 20.3 Enhanced optical properties of gold nanoparticles resulting from the interaction of light with a gold nanoparticle including absorption, Mie scattering, fluorescence and surface nhanced Raman scattering of adsorbed molecules. Reprinted with permission from ref 3. Copyright 2007 Future Medicine.

The excitation of the surface plasmon effect also induces strongly enhanced fluorescence properties of gold nanoparticles due to the enhanconent in the radiative rate of the inter-band electronic transitions relative to that in bulk metals. Metal nanoparticles, especially gold nanorods exhibit enhanced two-photon luminescence (TPL) and multi-photon luminescoice (MPL) [7, 8]. Strongly-enhanced TPL has been observed from individual particles [9, 10] and particle solutions [11] under femtosecond NIR laser excitation. This observation raises the possibility of nonlinear optical imaging in the NIR region, where water and biomolecules have... 

In the following, it will be demonstrated that confocal surface-enhanced Raman microscopy is a powerful tool for exploring optical and spectroscopic properties of molecules adsorbed on silver and gold nanoparticles. It is shown that confocal Raman microscopy coupled with high-resolution electron microscopy has the potential to deliver detailed information about the structure of points of high Raman intensity the so-called hot spots. 

Gold received much attention due to their unique size-dependent optical properties, insolubility in nitric acid and resistance to heat, moisture, oxygen and most corrosive reagents. For substrates in surface-enhanced Raman Spectroscopy (SERS), ergonomic electronic contacts, ultra fast data communication and biomedicine surface modified gold nanoparticles are perspective agents, while in the industry of catalysis platinum nanoparticles (Pt NPs) exhibiting excellent anticorrosive and catalytic properties are usually employed. 

Fukumi, K., (ihayahara, A., Kadono, K., Sakaguchi, T., Horino, Y., Miya, M., Fujii, K., Hayakawa, J.. Satou, M. Gold nanoparticles ion implanted in glass with enhanced nonlinear optical properties. J. Appl. Phys. 75, 3075-3080 (1994)... 

Gold nanoparticles (Au-NPs) and silver nanoparticles (Ag-NPs) are of particular interest in DNA sensors and immunosensors due to their advantageous properties, such as hydrophilicity, standard fabrication methods, excellent biocompatibility, unique characteristics in the conjugation with biological recognition elements, and multiplex capacity for signal transducer. Therefore, a large number of published methods use Au- or Ag-NPs in DNA [16,17,18] protein [19] and even cell [20] electrochemical detection besides optical detections like ICP-MS [21] or their use as ELISA enhancer [22]. 

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