scholarly journals Optical Micro/Nanofiber-Based Localized Surface Plasmon Resonance Biosensors: Fiber Diameter Dependence

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3295 ◽  
Author(s):  
Kaiwei Li ◽  
Wenchao Zhou ◽  
Shuwen Zeng

Integration of functional nanomaterials with optical micro/nanofibers (OMNFs) can bring about novel optical properties and provide a versatile platform for various sensing applications. OMNFs as the key element, however, have seldom been investigated. Here, we focus on the optimization of fiber diameter by taking micro/nanofiber-based localized surface plasmon resonance sensors as a model. We systematically study the dependence of fiber diameter on the sensing performance of such sensors. Both theoretical and experimental results show that, by reducing fiber diameter, the refractive index sensitivity can be significantly increased. Then, we demonstrate the biosensing capability of the optimized sensor for streptavidin detection and achieve a detection limit of 1 pg/mL. Furthermore, the proposed theoretical model is applicable to other nanomaterials and OMNF-based sensing schemes for performance optimization.

Author(s):  
Wenying Ma ◽  
Fangrong Hu ◽  
Huan Yang ◽  
Weimin Wang

Metal nanoparticles have potential utilities in biochemical sensing applications owing to their localized surface plasmon resonance characteristics. To facilitate the application of localized surface plasmon resonance sensors, a simple and effective interpretation of spectra responses of metal nanoparticles to analyte was developed in this paper. Based on a bilayer structure model and a trilayer structure model, a general relationship between the peak wavelength changes of extinction spectra and the thickness of the receptor layer as well as the analyte layer was established. Both analytical analysis and chloroform vapor test experiment demonstrate that the sensing performance is greatly dependent on the receptor thickness, and a thinner receptor layer will induce a greater sensitivity. These insights can be used as guidelines in fabricating highly sensitive localized surface plasmon resonance-based biochemical sensors.


NANO ◽  
2019 ◽  
Vol 14 (06) ◽  
pp. 1950071
Author(s):  
Haiwei Mu ◽  
Jianxin Wang ◽  
Qiang Liu ◽  
Wei Liu ◽  
Xianli Li ◽  
...  

The extinction spectral properties based on localized surface plasmon resonance (LSPR) of the concentric dual-ring nanodisk (CDRN) structure are investigated by discrete dipole approximation (DDA) and plasmon hybridization theory. The CDRN nanostructure shows flexible tunable multipole resonances in the near-infrared regime and the coupled resonance wavelengths depend on the structural parameters of the nanostructure, which has great potential in multichannel LSPR-based bio-sensing applications.


Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 246 ◽  
Author(s):  
Nuno M. Figueiredo ◽  
Filipe Vaz ◽  
Luís Cunha ◽  
Albano Cavaleiro

Localized surface plasmon resonance (LSPR) gas sensors are gaining increasing importance due to their unique tuneable functional properties. Au-WO3−x nanocomposite coatings, in particular, can be outstandingly sensitive to many different gases. However, a proper understanding of their optical properties and the way in which those properties are correlated to their structure/microstructure, is still needed. In this work, Au-WO3 nanocomposite coatings, with Au contents between 0–11 atomic percent, were grown using reactive magnetron co-sputtering technique and were characterized concerning their optical response. The precipitation of Au nanoparticles in the oxide matrix was promoted through thermal annealing treatments until 500 °C. Along with the Au nanoparticles’ morphological changes, the annealing treatments stimulated the crystallization of WO3, together with the appearance of oxygen-deficient WO3−x phases. Through theoretical simulations, we have related the LSPR effect with the different structural and morphological variations (namely, size and distribution of the nanoparticles and their local environment), which were a function of the Au content and annealing temperature. Our results suggest that local voids were present in the vicinity of the Au nanoparticles, for all temperature range, and that they should be present in a wide variety of Au-WO3 nanocomposites. A theoretical study concerning the refractive index sensitivity was carried out in order to predict the optimal coating design parameters for gas sensing experiments.


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