ABSTRACT
The nanoscale coating of colloid particles with a thin metallic layer to form core-shell nanoparticles or
the so-called metallic nanoshells is an active area of research in nanoscience and nanotechnology. Two of
the most commonly used metals for the synthesis of metallic nanoshells are gold and silver. It has been
experimentally confirmed that the optical response of these metallic nanoshells is determined by the
nanoparticle plasmon, which can be interpreted using the Mie scattering theory [1]. Theoretically, one
can shift the plasmon resonance to any desired wavelength in the visible and infrared ranges by varying
the size ratio of the nanoparticle core and the surrounding metallic shell. This excellent structural
tunability of the plasmon resonances in metallic nanoshells makes these nanoparticles particularly
attractive for many fundamental and practical applications. To date, metallic nanoshells have found
many applications in biology and medicine such as gene diagnostics and bioimaging [2], whole-blood
immunoassay [3], intracellular analysis [4-6], cancer imaging and therapy [7,8], photoacoustic tomo-
graphy [9], and drug delivery [10], among others.
