Department of Biomechatronics Engineering, National Pingtung University of Science and Technology, Pingtung 912, Taiwan.
Department of Chemistry and Biochemistry and Center for Nano Bio-Detection, National Chung Cheng University, Chiayi 621, Taiwan.
Sensors (Basel). 2018 May 31;18(6):1759. doi: 10.3390/s18061759.
A simple theoretical model was developed to analyze the extinction spectrum of gold nanoparticles (AuNPs) on the fiber core and glass surfaces in order to aid the determination of the surface coverage and surface distribution of the AuNPs on the fiber core surface for sensitivity optimization of the fiber optic particle plasmon resonance (FOPPR) sensor. The extinction spectrum of AuNPs comprises of the interband absorption of AuNPs, non-interacting plasmon resonance (PR) band due to isolated AuNPs, and coupled PR band of interacting AuNPs. When the surface coverage is smaller than 12.2%, the plasmon coupling effect can almost be ignored. This method is also applied to understand the refractive index sensitivity of the FOPPR sensor with respect to the non-interacting PR band and the coupled PR band. In terms of wavelength sensitivity at a surface coverage of 18.6%, the refractive index sensitivity of the coupled PR band (205.5 nm/RIU) is greater than that of the non-interacting PR band (349.1 nm/RIU). In terms of extinction sensitivity, refractive index sensitivity of the coupled PR band (-3.86/RIU) is similar to that of the non-interacting PR band (-3.93/RIU). Both maximum wavelength and extinction sensitivities were found at a surface coverage of 15.2%.
为了辅助确定光纤表面金纳米粒子（AuNPs）的表面覆盖率和分布，以优化光纤等离子体体共振（FOPPR）传感器的灵敏度，我们开发了一个简单的理论模型，用于分析光纤芯和玻璃表面上 AuNPs 的消光谱。AuNPs 的消光谱包括 AuNPs 的带间吸收、孤立 AuNPs 的非相互作用等离子体共振（PR）带以及相互作用 AuNPs 的耦合 PR 带。当表面覆盖率小于 12.2%时，等离子体耦合效应几乎可以忽略不计。该方法还可用于理解非相互作用 PR 带和耦合 PR 带对 FOPPR 传感器折射率灵敏度的影响。在 18.6%的表面覆盖率下，耦合 PR 带的波长灵敏度（205.5nm/RIU）大于非相互作用 PR 带的波长灵敏度（349.1nm/RIU）。在消光灵敏度方面，耦合 PR 带的折射率灵敏度（-3.86/RIU）与非相互作用 PR 带的折射率灵敏度（-3.93/RIU）相似。在表面覆盖率为 15.2%时，同时达到了最大波长和消光灵敏度。
