Subdiffraction limited, remote excitation of surface enhanced Raman scattering.
We demonstrate that focused laser excitation at the end of silver nanowires of 50-150 nm diameter excites SERS hot-spots at points of nanoparticle adsorption many micrometers along the wire due to the plasmon waveguide effect. The total SERS intensity detected at the hot-spots following wire-end excitation correlates with the known wavelength, polarization, and distance dependences of surface plasmon polariton (SPP) propagation in nanowires. The SERS spectra obtained at the hot-spots following wire-end excitation show very little background compared to when excitation occurs directly at the hot-spot, suggesting that a much smaller SERS excitation volume is achieved by remote, waveguide excitation. The ability to transfer SERS excitation over several micrometers, through a structure with a subdiffraction limit diameter, is discussed with respect to potential high-resolution SERS imaging applications.
Hutchison
James A
JA
Division of Molecular and Nano Materials, Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, Heverlee 3001, Belgium.
Centeno
Silvia P
SP
Odaka
Hideho
H
Fukumura
Hiroshi
H
Hofkens
Johan
J
Uji-I
Hiroshi
H
D000327:Adsorption; D004574:Electromagnetic Fields; D008027:Light; D020527:Microscopy, Scanning Probe / Q000379:methods; D053758:Nanoparticles / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry; D053770:Nanowires / Q000737:chemistry; D010636:Phenols / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013499:Surface Properties
D037742:Nanotubes, Carbon; D010636:Phenols; D013438:Sulfhydryl Compounds; C042983:thiophenol