Sensitive label-free biosensors by using gap plasmons in gold nanoslits
Sensitive label-free biosensors by using gap plasmons in gold nanoslits
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DOI：
10.1016/j.bios.2008.03.044
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发表时间：
2008-10-15
影响因子：
12.6
通讯作者：
Wei, Pei-Kuen
中科院分区：
文献类型：
--
作者：
Lee, Kuang-Li;Wang, Way-Seen;Wei, Pei-Kuen
研究了金纳米缝阵列中间隙等离子体的探测灵敏度，并与外表面的表面等离子体进行了比较。在130 nm厚的金膜中制造具有各种狭缝宽度的纳米狭缝阵列。对于横磁（TM）入射波，600 nm周期的纳米缝阵列显示出两个可区分的透射峰，分别对应于间隙等离子体和表面等离子体的共振。通过在纳米狭缝阵列上涂覆薄SiO2膜和不同的生物分子，比较了两种模式的表面灵敏度。我们的实验结果验证了间隙等离子体比传统的表面等离子体更敏感。其探测灵敏度随狭缝宽度的减小而增大。对于小于30 nm的狭缝宽度，差距等离激元比表面等离激元敏感一个数量级。我们将这种高灵敏度归因于生物分子和纳米尺寸的间隙等离子体之间的大重叠。(C)2008 Elsevier B.V.保留所有权利。
The detection sensitivities of gap plasmons in gold nanoslit arrays are studied and compared with surface plasmons on outside surface. The nanoslit arrays were fabricated in a 130 nm-thick gold film with various slit widths. For transverse-magnetic (TM) incident wave, the 600 nm-period nanoslit array shows two distinguishable transmission peaks corresponding to the resonances of gap plasmons and surface plasmons, respectively. The surface sensitivities for both modes were compared by coating thin SiO2 film and different biomolecules on the nanoslit arrays. Our experimental results verify gap plasmons are more sensitive than conventional surface plasmons. its detection sensitivity increases with the decrease of slit width. The gap plasmon is one order of magnitude sensitive than the surface plasmon for slit widths smaller than 30 nm. We attribute this high sensitivity to the large overlap between biomolecules and nanometer-sized gap plasmons. (C) 2008 Elsevier B.V. All rights reserved.