Plasmonic Coupling Effect on Spectral Response of Silver Nanoparticles Immobilized on an Optical Fiber Sensor
Plasmonic Coupling Effect on Spectral Response of Silver Nanoparticles Immobilized on an Optical Fiber Sensor
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DOI：
10.1021/jp401542a
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发表时间：
2013-08-22
影响因子：
3.7
通讯作者：
Kundu, Tapenendu
中科院分区：
文献类型：
--
作者：
Dutta, Rani;Singh, Bhanu P.;Kundu, Tapenendu
研究了银纳米粒子在U型弯曲传感光纤探针上的局域表面等离子体共振（LSPR）。由于光纤表面纳米颗粒数量的增加，峰值共振的波长逐渐偏移，这归因于等离子体激元耦合效应。由于固定是随机的，共振的位移以及吸收光谱的加宽取决于纳米颗粒的分布。得到.为了深入了解这种光谱行为的原因，我们采用了两粒子耦合近似，并假设粒子与其最近的邻居形成对。从纤维表面的微观图像中获得了对的分布。利用离散偶极子近似（DDA）的理论框架计算了这些对的贡献的集体响应。共振的位移以及加宽的计算光谱被发现是在良好的协议与实验观察到的光谱。因此，该方法可用于通过利用贵金属纳米颗粒之间的等离子体激元耦合来调节和增强灵敏度，以用于设计和制造基于LSPR的光学传感器。
The localized surface plasmon resonance (LSPR) of silver nanoparticles during immobilization on the U-bent sensor fiber probe has been studied. The gradual wavelength shift of the peak resonance due to the increment of the number of nanoparticles on the fiber surface has been attributed to the plasmonic coupling effect. Since the immobilization is random, the shift of the resonance as well as the broadening of the absorption spectrum depends on the distribution of the nanoparticles. To get. the insight of the cause of this spectral behavior, we have incorporated the two-particle coupling approximation and assumed that the particles form pairs with its nearest neighbors. The distribution of pairs was obtained from the microdimensional images of fiber surfaces. The collective response from the contributions of these pairs was calculated using the theoretical framework of discrete dipole approximation (DDA). The shifts of the resonance as well as the broadening of the calculated spectra were found to be in excellent agreement with those of the experimentally observed spectra. Thus, this methodology can be utilized for tuning and enhancing the sensitivity by exploiting the plasmonic coupling between the noble metal nanoparticles for designing and fabricating the LSPR based optical sensor.