Locally excited surface plasmon resonance for refractive index sensing with high sensitivity and high resolution

2021 ◽  
Author(s):  
Xue Wang ◽  
Chang Wang ◽  
Xiaojuan Sun ◽  
Xin Li ◽  
Hongyao Liu ◽  
...  
2018 ◽  
Vol 8 (7) ◽  
pp. 1172 ◽  
Author(s):  
Nunzio Cennamo ◽  
Luigi Zeni ◽  
Ester Catalano ◽  
Francesco Arcadio ◽  
Aldo Minardo

In this paper, we show that light-diffusing fibers (LDF) can be efficiently used as host material for surface plasmon resonance (SPR)-based refractive index sensing. This novel platform does not require a chemical procedure to remove the cladding or enhance the evanescent field, which is expected to give better reproducibility of the sensing interface. The SPR sensor has been realized by first removing the cladding with a simple mechanical stripper, and then covering the unclad fiber surface with a thin gold film. The tests have been carried out using water–glycerin mixtures with refractive indices ranging from 1.332 to 1.394. The experimental results reveal a high sensitivity of the SPR wavelength to the outer medium’s refractive index, with values ranging from ~1500 to ~4000 nm/RIU in the analyzed range. The results suggest that the proposed optical fiber sensor platform could be used in biochemical applications.


2010 ◽  
Vol 1253 ◽  
Author(s):  
Pei-Yu Chung ◽  
Kuang-Li Lee ◽  
Gregory Schultz ◽  
Pei-Kuen Wei ◽  
Christopher Batich

AbstractSurface plasmon resonance (SPR) biosensors are widely used in sensitive chemical, biological and environmental sensing. Recently, the studies of nano-plasmonics in metallic structures have shown that surface plasmons can also be excited by the metallic nanostructures films which can be used for high-throughput and chip-based SPR type sensing. We developed a class of plasmonic crystal-like structures consisting of a film with arrays of periodic nanoslit geometry. Because the engineered array ensures multiple resonance modes, we use the multispectral analysis to evaluate the refractive index sensing capability. Different from the common method monitoring a single peak shift, the multispectral analysis, observing all the peak shifts and intensity changes in the multiple plasmonic resonances in the spectra, can improve the signal-to-noise ratio of the system and enhance the sensing capabilities. In this investigation, we studied the best condition for the gold nanoslit arrays by testing their ability for refractive index sensing, and a high sensitivity of up to 28586 %T nm/RIU was obtained by multispectral analysis (RIU = refreactive index unit, and T= transmission).


Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1325 ◽  
Author(s):  
Ru-Jing Sun ◽  
Hung Ji Huang ◽  
Chien-Nan Hsiao ◽  
Yu-Wei Lin ◽  
Bo-Huei Liao ◽  
...  

A TiN-based substrate with high reusability presented high-sensitivity refractive index measurements in a home-built surface plasmon resonance (SPR) heterodyne phase interrogation system. TiN layers with and without additional inclined-deposited TiN (i-TiN) layers on glass substrates reached high bulk charge carrier densities of 1.28 × 1022 and 1.91 × 1022 cm−3, respectively. The additional 1.4 nm i-TiN layer of the nanorod array presented a detection limit of 6.1 × 10−7 RIU and was higher than that of the 46 nm TiN layer at 1.2 × 10−6 RIU when measuring the refractive index of a glucose solution. Furthermore, the long-term durability of the TiN-based substrate demonstrated by multiple processing experiments presented a high potential for various practical sensing applications.


Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6164
Author(s):  
Treesukon Treebupachatsakul ◽  
Siratchakrit Shinnakerdchoke ◽  
Suejit Pechprasarn

This paper provides a theoretical framework to analyze and quantify roughness effects on sensing performance parameters of surface plasmon resonance measurements. Rigorous coupled-wave analysis and the Monte Carlo method were applied to compute plasmonic reflectance spectra for different surface roughness profiles. The rough surfaces were generated using the low pass frequency filtering method. Different coating and surface treatments and their reported root-mean-square roughness in the literature were extracted and investigated in this study to calculate the refractive index sensing performance parameters, including sensitivity, full width at half maximum, plasmonic dip intensity, plasmonic dip position, and figure of merit. Here, we propose a figure-of-merit equation considering optical intensity contrast and signal-to-noise ratio. The proposed figure-of-merit equation could predict a similar refractive index sensing performance compared to experimental results reported in the literature. The surface roughness height strongly affected all the performance parameters, resulting in a degraded figure of merit for surface plasmon resonance measurement.


Micromachines ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 640 ◽  
Author(s):  
Xudong Li ◽  
Shuguang Li ◽  
Xin Yan ◽  
Dongming Sun ◽  
Zheng Liu ◽  
...  

In this paper we propose a gold-plated photonic crystal fiber (PCF) refractive index sensor based on surface plasmon resonance (SPR), in which gold is coated on the external surface of PCF for easy fabrication and practical detection. The finite element method (FEM) is used for the performance analysis, and the numerical results show that the thickness of the gold film, the refractive index of the analyte, the radius of the air hole in the first layer, the second layer, and the central air hole can affect the sensing properties of the sensor. By optimizing the sensor structure, the maximum wavelength sensitivity can reach 11000 nm/RIU and the maximum amplitude sensitivity can reach 641 RIU−1. Due to its high sensitivity, the proposed sensor can be used for practical biological and chemical sensing.


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