ABSTRACT
The advent of nanotechnology introduced a variety of novel exciting possibilities into diagnostic and sensing applications. Noble metal nanoparticles are of special relevance in that context, because their unusual properties fall mainly in visible, but also near-infrared and near-ultraviolet range, depending on the nanoparticle size and kind of a metal. Nanoparticles interact strongly with light via resonant excitation of localized surface plasmons (LSPs), and so can act as efficient receiving or/and scattering optical nanoantennas. Resonant excitation of LSP give rise to a variety of effects, such as frequency-dependent absorption and scattering (resulting in bright colors of colloids of nanoparticles) and electromagnetic near-field concentration and enhancement. An intense interest in noble-metal nanoparticles is driven by diverse applications in sensing, biomedical diagnostics, and therapy, energy transport and conversion, novel spectroscopic and microscopic techniques, novel (meta-) materials and others.
