Figures of Merit for Refractometric LSPR Biosensing
Figures of Merit for Refractometric LSPR Biosensing
复制标题
折射法 LSPR 生物传感的品质因数
DOI：
10.1007/978-1-4614-3933-2_13
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发表时间：
2012
影响因子：
2.1
通讯作者：
B. Sepúlveda
中科院分区：
文献类型：
--
作者：
M. A. Otte;B. Sepúlveda
本章的目的是描述路线，以改善等离子体纳米粒子的折射率为基础的生物传感器的功能。利用其局域表面等离子体共振（LSPR）的可调谐性，我们探索了作为LSPR光谱位置的函数的传感性能。首先，我们展示了在波长和能量尺度上的灵敏度描述可能产生的模糊性。然而，我们将看到如何通过引入品质因数（FOM）来规避这种模糊性，该品质因数被定义为灵敏度和共振峰宽度之间的商，因为该参数在能量和波长尺度上是等效的。光谱分析表明，接近金属表面的折射率的局部变化的灵敏度可以是可比的，甚至大于传统的SPR传感器时，适当地选择纳米粒子的共振位置。事实上，对于一个固定的纳米粒子体积，我们表明，表面灵敏度只取决于共振的光谱位置，而颗粒的形状只起次要作用。此外，FOM显示了优化的光谱区域，在金的情况下位于700和900 nm之间，这与金属的介电常数的真实的部分和虚部之间的商最大化的区域一致。
The aim of this chapter is to describe routes to improve the features of plasmonic nanoparticles as refractometric based biosensors. Taking advantage of the tunability of their localized surface plasmon resonance (LSPR), we explore the sensing performance as a function of the LSPR spectral position. Firstly, we show the ambiguities that can arise from the description of the sensitivity in the wavelength and energy scales. However, we will see how such ambiguities can be circumvented with the introduction of the figure of merit (FOM), defined as the quotient between sensitivity and width of the resonance peaks, since this parameter is equivalent in both energy and wavelength scales. The spectral analysis reveals that the sensitivity to local changes of refractive index close to the metal surface can be comparable or even larger than that of conventional SPR sensors when the resonance position of the nanoparticles is properly selected. Indeed, for a fixed nanoparticle volume, we show that the surface sensitivity only depends on the spectral position of the resonance, whereas the shape of the particle only plays a secondary role. In addition, the FOM displays an optimized spectral region, located between 700 and 900 nm in the case of gold, which coincides with the region where the quotient between real and imaginary parts of the dielectric constant of the metal is maximized.