INFIQC   05475
INSTITUTO DE INVESTIGACIONES EN FISICO- QUIMICA DE CORDOBA
Unidad Ejecutora - UE
artículos
Título:
Gap structure effects on SERS intensities for gold gapped-rods
Autor/es:
SHUZHOU LI, MARÍA L. PEDANO, GILBERT CHANG, CHAD A. MIRKIN, AND GEORGE C. SCHATZ.
Revista:
NANO LETTERS (PRINT)
Editorial:
American Chemical Society
Referencias:
Lugar: Washington; Año: 2010 vol. 10 p. 1722 - 1727
ISSN:
1530-6984
Resumen:
Gapped-rods provide a unique platform for elucidating structure/function relationships, both for single-molecule electrochemical techniques and for surface enhanced Raman scattering (SERS). This manuscript attempts to elucidate the dependence of SERS intensities on gap topography and gap distance for gold gapped-rods with segment lengths varying over a wide range (40-2000 nm). Significantly, we have determined that rough gaps lead to a smaller SERS enhancement than smooth gaps for these structures even though the rough gaps have a larger total surface area. Both theory and experiment show periodic variation of SERS intensity with segment length as determined by odd-symmetry plasmon multipoles. Excitation of even-symmetry modes is dipole forbidden (for polarization along the rod axis), but this selection rule can be relaxed by roughness or, for smooth gaps, by near-field coupling between the rod segments.