Highly Sensitive Plasmonic Silver Nanorods
Highly Sensitive Plasmonic Silver Nanorods
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DOI：
10.1021/nn200877b
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发表时间：
2011-09-01
期刊：
影响因子：
17.1
通讯作者：
Soennichsen, Carsten
中科院分区：
文献类型：
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作者：
Jakab, Arpad;Rosman, Christina;Soennichsen, Carsten
我们通过监测从水到12.5%蔗糖溶液的等离子体共振位移，比较了具有相似共振波长的银和金纳米棒的单粒子等离子体灵敏度。我们发现银纳米粒子的灵敏度是金的1.2-2倍，这与基于边界元方法(BEM)的模拟结果很好地吻合。为了排除颗粒体积对灵敏度的影响，我们测试了在给定共振波长下随着颗粒宽度的增加而增加的金棒。利用金属光学性质的Drude模型和定域表面等离子体的准静态近似(QSA)，我们证明了银的高灵敏度的主要贡献是d带电子的低背景极化率，并提供了一个简单的灵敏度公式。我们提高了银纳米棒传感器的可逆性。通过阻挡照明光的高能部分来重复环境变化的循环。
We compare the single-particle plasmonic sensitivity of silver and gold nanorods with similar resonance wavelengths by monitoring the plasmon resonance shift upon changing the environment from water to 12.5% sucrose solution. We find that silver nanoparticles have 1.2 to 2 times higher sensitivity than gold, in good agreement with simulations based on the boundary-elements-method (BEM). To exclude the effect of particle volume on sensitivity, we test gold rods with increasing particle width at a given resonance wavelength. Using the Drude-model of optical properties of metals together with the quasi-static approximation (QSA) for localized surface plasmons, we show that the dominant contribution to higher sensitivity of silver is the lower background polarizability of the d-band electrons and provide a simple formula for the sensitivity. We improve the reversibility of the silver nanorod sensors. upon repeated cycles of environmental changes by blocking the high energy parts of the illumination light.