Probing a Century Old Prediction One Plasmonic Particle at a Time
- 2 March 2010
- journal article
- Published by American Chemical Society (ACS) in Nano Letters
- Vol. 10 (4), 1398-1404
- https://doi.org/10.1021/nl100199h
Abstract
In 1908, Gustav Mie solved Maxwell’s equations to account for the absorption and scattering of spherical plasmonic particles. Since then much attention has been devoted to the size dependent optical properties of metallic nanoparticles. However, ensemble measurements of colloidal solutions generally only yield the total extinction cross sections of the nanoparticles. Here, we show how Mie’s prediction on the size dependence of the surface absorption and scattering can be probed separately for the same gold nanoparticle by using two single particle spectroscopy techniques, (1) dark-field scattering and (2) photothermal imaging, which selectively only measure scattering and absorption, respectively. Combining the optical measurements with correlated scanning electron microscopy furthermore allowed us to measure the size of the spherical gold nanoparticles, which ranged from 43 to 274 nm in diameter. We found that even though the trend predicted by Mie theory is followed well by the experimental data over a large range of nanoparticle diameters, for small size variations changes in scattering and absorption intensities are dominated by factors other than those considered by Mie theory. In particular, spectral shifts of the plasmon resonance due to deviations from a spherical particle shape alone cannot explain the observed variation in absorption and scattering intensities.Keywords
This publication has 50 references indexed in Scilit:
- PlasMOStor: A Metal−Oxide−Si Field Effect Plasmonic ModulatorNano Letters, 2009
- Circuits with Light at Nanoscales: Optical Nanocircuits Inspired by MetamaterialsScience, 2007
- Plasmonics: Merging Photonics and Electronics at Nanoscale DimensionsScience, 2006
- A molecular ruler based on plasmon coupling of single gold and silver nanoparticlesNature Biotechnology, 2005
- Nanostructures in BiodiagnosticsChemical Reviews, 2005
- Single Silver Nanoparticles as Real-Time Optical Sensors with Zeptomole SensitivityNano Letters, 2003
- Biomolecular Recognition Based on Single Gold Nanoparticle Light ScatteringNano Letters, 2003
- Single-target molecule detection with nonbleaching multicolor optical immunolabelsProceedings of the National Academy of Sciences of the United States of America, 2000
- Onset of Catalytic Activity of Gold Clusters on Titania with the Appearance of Nonmetallic PropertiesScience, 1998
- Light-Scattering Submicroscopic Particles as Highly Fluorescent Analogs and Their Use as Tracer Labels in Clinical and Biological ApplicationsAnalytical Biochemistry, 1998