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2009, 113, 40–44 Published on Web 12/15/2008
Localized and Propagating Surface Plasmons in Gold Particles of Near-Micron Size Ludovic S. Live, Marie-Pier Murray-Me´thot, and Jean-Francois Masson* De´partement de Chimie, UniVersite´ de Montre´al, C.P. 6128 Succ. Centre-Ville, Montre´al, QC, Canada H3C 3J7 ReceiVed: NoVember 27, 2008
In this letter, we demonstrate that Au triangles between approximately 200 nm and 1.5 µm are transitioning from a predominantly localized surface plasmon resonance (LSPR) character to a regime where both LSPR and a short-range SPR mode are concomitantly present. The Au triangles are active in LSPR between approximately λ ) 700 nm for the smaller triangles and λ ) 2.5 µm for the largest Au triangles. Triangles with a base length of 200 and 300 nm do not exhibit an active short-range SPR mode, while triangles with 500 and 700 nm and 1.5 µm base lengths show a strong absorption peak in SPR at approximately λ ) 800 nm, attributed to the short-range SPR mode. A low sensitivity of
