On the Use of Plasmonic Nanoparticle Pairs As a Plasmon Ruler: The Dependence of the Near-Field Dipole Plasmon Coupling on Nanoparticle Size and Shape
On the Use of Plasmonic Nanoparticle Pairs As a Plasmon Ruler: The Dependence of the Near-Field Dipole Plasmon Coupling on Nanoparticle Size and Shape
复制标题
DOI：
10.1021/jp807904s
复制
发表时间：
2009-03-12
影响因子：
2.9
通讯作者：
El-Sayed, Mostafa A.
中科院分区：
文献类型：
--
作者：
Tabor, Christopher;Murali, Raghunath;El-Sayed, Mostafa A.
金或银纳米颗粒的局域表面等离子体共振（LSPR）谱带被观察到由于另一纳米颗粒的近场等离子体场而发生偏移。所观察到的位移对粒子间距离的依赖性被用作生物系统中的标尺，并产生了等离子体标尺方程，其中发现偶极共振中的分数位移随着以颗粒尺寸为单位的粒子间分离以指数方式减小。观察到的指数衰减长度常数是一致的小范围的纳米颗粒的尺寸，形状和类型的金属。该方程是从圆盘和球形纳米颗粒上观察到的结果推导出来的，并使用DNA缀合纳米球系统的结果进行了证实。本论文的目的是使用电子束光刻和DDA计算来检查等离子体标尺方程中的指数衰减长度值对颗粒尺寸和形状的恒定性，所述颗粒包括不同对称性和取向的纳米颗粒。结果表明，该指数几乎与纳米颗粒的尺寸无关，但对形状非常敏感。讨论的纳米粒子最适合在生物系统中的不同应用和比较的等离子体标尺与福斯特共振能量转移（FRET）提到。
The localized surface plasmon resonance (LSPR) spectral band of a gold or silver nanoparticle is observed to shift as a result of the near-field plasmonic field of another nanoparticle. The dependence of the observed shift on the interparticle distance is used as a ruler in biological systems and gave rise to a plasmonic ruler equation in which the fractional shift in the dipole resonance is found to decrease near exponentially with the interparticle separation in units of the particle size. The exponential decay length constant was observed to be consistent among a small range of nanoparticle sizes, shapes, and types of metal. The equation was derived from the observed results on disks and spherical nanoparticles and confirmed using results on a DNA conjugated nanosphere system. The aim of the present paper is to use electron beam lithography and DDA calculations to examine the constancy of the exponential decay length value in the plasmonic ruler equation on particle size and shape of a number of particles including nanoparticles of different symmetry and orientations. The results suggest that the exponent is almost independent of the size of the nanoparticle but very sensitive to the shape. A discussion of the nanoparticles most suitable for different applications in biological systems and a comparison of the plasmonic ruler with Forster resonance energy transfer (FRET) is mentioned.