The dielectric coating-induced widening of the longitudinal surface plasmon resonance (SPR) band of gold nanorods was investigated theoretically. The line width of the longitudinal SPR could be enlarged by increasing the thickness or the dielectric constant of the coated dielectric shell. The corresponding physical origin has been illuminated by the dielectric coating-enhanced anisotropic distribution of the surface charge. This dielectric coating-dependent widening of the longitudinal SPR presents a new biologic sensing picture based on tuning the line width of the plasmonic absorption band of metallic nanostructure.
展开▼
