Spatially Inhomogeneous Enhancement of Fluorescence by a Monolayer of Silver Nanoparticles

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• 作者：Anatoli Ianoul ; Andrew Bergeron
• 刊名：Langmuir
• 出版年：2006
• 出版时间：November 21, 2006
• 年：2006
• 卷：22
• 期：24
• 页码：10217 - 10222
• 全文大小：597K
• 年卷期：v.22,no.24(November 21, 2006)
• ISSN：1520-5827

文摘

Near-field scanning optical microscopy (NSOM) was applied to study the effect of a two-dimensional array of silvernanoparticles on the spatial distribution and magnitude of fluorescence signal enhancement for a monolayer of Rhodamine6G (Rh6G). Twenty polyelectrolyte monolayers were deposited between the nanoparticles and the dye by a layer-by-layer deposition technique resulting in a 15-20 nm separation cushion, necessary to minimize the fluorescencesignal quenching. The fluorescence signal in NSOM images was found to be distributed inhomogeneously as small(100-200 nm in diameter) fluorescent clusters with typically 5-30 times higher fluorescence intensities than a samplewithout nanoparticles. The position and relative intensity of the clusters was found to be dependent on the excitationwavelength, suggesting that the enhancement originates from the nanoparticle surface plasmon resonance.