Nanoshells have been previously shown to tune absorption
frequencies
efficiently. What will happen when a nanoshell embeds on a small core
system? A theoretical model that a core composed of gold is embedded
within a nanoshell of Au/Ag is constructed to answer this question.
The calculations based on the discrete dipole approximation (DDA)
method are performed and proved to converge accurately by satisfying
the usual criteria related to the applicability of the DDA. The results
show that the nanoshells in the core/shell system greatly influence
the surface plasmon resonance (SPR). Indeed, the shell frequency is
tuned to match the optical properties of the absorbing core leading
to hybridization/mixing and possibly overall enhancement of absorption
cross-section. The calculation of the field enhancement also shows
that the location of the field enhancement is specified by the different
resonance patterns.
Ag semishells (AgSS) ordered arrays for surface-enhanced Raman scattering (SERS) spectroscopy have been prepared by depositing Ag film onto polystyrene colloidal particle (PSCP) monolayer templates array. The diversified activity for SERS activity with the ordered AgSS arrays mainly depends on the PSCP diameter and Ag film thickness. The high SERS sensitivity and reproducibility are proved by the detection of rhodamine 6G (R6G) and 4-aminothiophenol (4-ATP) molecules. The prominent enhancements of SERS are mainly from the “V”-shaped or “U”-shaped nanogaps on AgSS, which are experimentally and theoretically investigated. The higher SERS activity, stability and reproducibility make the ordered AgSS a promising choice for practical SERS low concentration detection applications.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.