"DNA-mediated Anomalous Optical Coupling of Heterogeneous Metallic Nanostructures"
"DNA-mediated Anomalous Optical Coupling of Heterogeneous Metallic Nanostructures"
复制标题
“DNA介导的异质金属纳米结构的异常光学耦合”
DOI：
10.1021/jp501613b
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
T. Iida*
中科院分区：
文献类型：
--
作者：
S. Tokonami*;K. Nishida;S. Hidaka;Y. Yamamoto;H. Nakao;T. Iida*
在相互作用的金属纳米结构中，局域表面等离子体激元（LSPs）的增强光学响应为检测生物小分子提供了一条很有前途的途径，而在不同种类的金属纳米结构与通过小分子的纳米尺度分离的耦合下，LSPs将获得非常规的光谱调制。在这里，我们意外地发现了来自异质金属纳米结构的光散射的异常条件，即，银纳米颗粒固定珠（AgNP-FB）和金纳米棒（AuNRs）通过DNA偶联，其中光散射在宽UV区域显著抑制，但在可见光区域增强。基于簇近似下的超快计算，这种异常归因于单个AgNP-FB中AuNR和LSP的带间跃迁集体模式的宽带抵消。这种机制具有很高的潜力，即使在白色光源下也可应用于zmol级DNA的检测。
The enhanced optical response due to localized surface plasmons (LSPs) in interacting metallic nanostructures provides a promising avenue for the detecting small biological molecules, whereas an unconventional spectral modulation of LSPs would be obtained under the coupling of the different kinds of metallic nanostructures with nanoscale separations via small molecules. Here, we unexpectedly found an anomalous condition of light scattering from heterogeneous metallic nanostructures, i.e., silver-nanoparticle fixed bead (AgNP-FB) and gold nanorods (AuNRs) coupled via DNA, in which the light scattering dramatically suppressed in the broad UV region although it was enhanced in the visible region. Based on ultrafast computation under cluster approximation, this anomaly was attributed to the broadband cancellation of collective modes of interband transitions in AuNRs and LSPs in a single AgNP-FB. This mechanism has a high potential to apply for detection of DNA in zmol order even under white light source.