Study on the sensitivity enhancement of fiber SPR sensor by gold nanorods

Sensor Review ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Rui Wang ◽  
Chunlan Liu ◽  
Yong Wei ◽  
Yudong Su
Keyword(s):  
Refractive Index ◽  
Parameter Optimization ◽  
Gold Nanorods ◽  
Sensitivity Enhancement ◽  
Gold Nanorod ◽  
Enhancement Effect ◽  
Content Type ◽  
Spr Sensor ◽  
Aspect Ratios ◽  
Validation Experiments

Purpose This paper aims to study the sensitivity enhancement effect of the gold nanorod on fiber surface plasmon resonance (SPR) sensor. It proposes modeling the sensing effects of fiber SPR sensor decorated with metal nanoparticles. By using simulation and experiment, the sensitivity enhancement effect of the gold nanorod was studied and demonstrated. Design/methodology/approach The paper opted for an exploratory study using simulation approach of finite-difference time-domain. Specifically, the effect of ratios and aspect ratios of gold nanorod on sensing performance are investigated theoretically. Based on the mathematical models, the validation experiments by using the gold nanorod with the aspect ratios of 5.1 were done to verify the sensitivity enhancement effect of the gold nanorod. Findings In conclusion, it is evident that with the increases of the aspect ratios, the sensing sensitivity of the refractive index increases first, then gradually stabilizes or decreases. After parameter optimization, the ratios and aspect ratios of gold nanorod are chosen to be 8 nm and 12.5, respectively, which makes the optimal refractive index sensitivity of 4465.53 nm/RIU be realized. In addition, the validation experiments by using the gold nanorod with the aspect ratios of 5.1 verify the sensitivity enhancement effect of the gold nanorods. Originality/value This paper proposes and demonstrates a new method for the sensitivity enhancement of fiber SPR sensor. After parameter optimization, the maximum sensitivity of 4465.53 nm/RIU was achieved by using 8 nm gold nanorods with the aspect ratios of 12.5. To verify the sensitivity enhancement of the gold nanorods, the authors also did the validation experiments. The testing results indicated that after the decoration of the gold nanorods, the sensitivity of the sensing probe increases from 2190.57 nm/RIU to 2693.24 nm/RIU, which demonstrates the sensitivity enhancement effect of the gold nanorods.

scholarly journals Plasmonic Sensing Characteristics of Gold Nanorods with Large Aspect Ratios

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3458 ◽  
Author(s):  
Chao Zhuang ◽  
Yifan Xu ◽  
Ningsheng Xu ◽  
Jinxiu Wen ◽  
Huanjun Chen ◽  
...  
Keyword(s):  
Refractive Index ◽  
Gold Nanorods ◽  
High Performance ◽  
Near Infrared ◽  
High Refractive Index ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sers Substrate ◽  
Refractive Index Sensitivity ◽  
Aspect Ratios ◽  
Plasmonic Sensing

Plasmonic gold nanorods play important roles in nowadays state-of-the-art plasmonic sensing techniques. Most of the previous studies and applications focused on gold nanorods with relatively small aspect ratios, where the plasmon wavelengths are smaller than 900 nm. Gold nanorods with large aspect ratios are predicted to exhibit high refractive-index sensitivity (Langmir 2008, 24, 5233–5237), which therefore should be promising for the development of high-performance plasmonic chemical- and bio-sensors. In this study, we developed gold nanorods with aspect ratios over 7.9, which exhibit plasmon resonances around 1064 nm. The refractive index (RI) sensitivity of these nanorods have been evaluated by varying their dielectric environment, whereby a sensitivity as high as 473 nm/RIU (refractive index unit) can be obtained. Furthermore, we have demonstrated the large-aspect-ratio nanorods as efficient substrate for surface enhanced Raman spectroscopy (SERS), where an enhancement factor (EF) as high as 9.47 × 108 was measured using 4-methylbenzenethiol (4-MBT) as probe molecule. Finally, a type of flexible SERS substrate is developed by conjugating the gold nanorods with the polystyrene (PS) polymer. The results obtained in our study can benefit the development of plasmonic sensing techniques utilized in the near-infrared spectral region.

scholarly journals Optimising gold nanorods for photoacoustic imaging in vitro

2019 ◽  
Vol 1 (4) ◽  
pp. 1472-1481 ◽  
Author(s):  
Oscar B. Knights ◽  
Sunjie Ye ◽  
Nicola Ingram ◽  
Steven Freear ◽  
James R. McLaughlan
Keyword(s):  
Gold Nanorods ◽  
Photoacoustic Imaging ◽  
Gold Nanorod ◽  
Aspect Ratios

A study to find the optimum sized gold nanorod for use in PA imaging and/or optical-based theranostics, by comparing four different sizes with similar aspect ratios.

Enhanced sensitivity of fiber SPR sensor by metal nanoparticle

Sensor Review ◽  
2020 ◽  
Vol 40 (3) ◽  
pp. 355-361 ◽  
Author(s):  
Chunlan Liu ◽  
Yang Gao ◽  
YaChen Gao ◽  
Yong Wei ◽  
Ping Wu ◽  
...  
Keyword(s):  
Refractive Index ◽  
Metal Nanoparticles ◽  
Dynamic Range ◽  
Cone Angle ◽  
Fiber Surface ◽  
Metal Nanoparticle ◽  
Surface Plasma Resonance ◽  
Content Type ◽  
Spr Sensor ◽  
Enhanced Sensitivity

Purpose This paper aims to clarify the relationship between the performance of the metal nanoparticles and the sensitivity of the fiber surface plasma resonance (SPR) sensor. It proposes modeling the sensing effects of a single-mode fiber SPR sensor with a cone angle structure decorated with metal nanoparticles. This study uses the metal nanoparticles to the realize enhanced sensitivity of refractive index sensing. Design/methodology/approach This paper opted for an exploratory study using a simulation approach of finite-difference time-domain (FDTD). Specifically, the effect of size, the material and the shape of the metal nanoparticle on sensing performance are investigated theoretically. Findings In conclusion, it is evident that the localized SPR (LSPR) effect weakens as the diameter of the gold nanosphere increases, the SPR effect enhances and the SPR sensitivity increases first and then decreases. The metal nanoparticle with the different materials and different shapes also have different LSPR and SPR sensitivity and wavelength length dynamic range. The investigation shows that, by changing parameters, the reflection spectra of the fiber SPR sensor exhibit an obvious transition from LSPR to SPR characteristics, and enhanced sensitivity of the refractive index is realized. Originality/value This paper fulfills an identified need to study how the sensitivity of the fiber SPR sensor can be enhanced by the metal nanoparticle. After the optimization of parameters, the sensitivity of 5,140 nm/RIU is achieved, which provides a new research direction for sensitivity enhancement of fiber SPR sensor.

scholarly journals Plasmonic Sensing Characteristics of Gold Nanorods with Large Aspect Ratios

2018 ◽  
Author(s):  
Chao Zhuang ◽  
Yifan Xu ◽  
Ningsheng Xu ◽  
Jinxiu Wen ◽  
Huanjun Chen ◽  
...  
Keyword(s):  
Refractive Index ◽  
Gold Nanorods ◽  
High Performance ◽  
Near Infrared ◽  
High Refractive Index ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sers Substrate ◽  
Refractive Index Sensitivity ◽  
Aspect Ratios ◽  
Plasmonic Sensing

Plasmonic gold nanorods play important roles in nowadays state-of-the-art plasmonic sensing techniques. Most of the previous studies and applications focused on gold nanorods with relatively small aspect ratios, where the plasmon wavelengths are smaller than 900 nm. Gold nanorods with large aspect ratios are predicted to exhibit high refractive-index sensitivity (Langmir 2008, 24, 5233–5237.), which therefore should be promising for developing of high-performance plasmonic chemical- and bio-sensors. In this study, we developed gold nanorods with aspect ratios over 7.9, which exhibit plasmon resonances around 1064 nm. The refractive index (RI) sensitivity of these nanorods have been evaluated by varying their dielectric environment, whereby a sensitivity as high as 473 nm/RIU can be obtained. Furthermore, we have demonstrated the large-aspect-ratio nanorods as efficient substrate for surface enhanced Raman spectroscopy (SERS), where an enhancement factor (EF) as high as 9.47×108 was measured using 4-methylbenzenethiol (4-MBT) as probe molecule. Finally, a type of flexible SERS substrate is developed by conjugating the gold nanorods with the polystyrene (PS) polymer. The results obtained in our study can benefit the development of plasmonic sensing techniques utilized in the near-infrared spectral region.

scholarly journals Effective replacement of cetyltrimethylammonium bromide (CTAB) by mercaptoalkanoic acids on gold nanorod (AuNR) surfaces in aqueous solutions

Nanoscale ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 658-668 ◽  
Author(s):  
Rafael del Caño ◽  
Jose M. Gisbert-González ◽  
Jose González-Rodríguez ◽  
Guadalupe Sánchez-Obrero ◽  
Rafael Madueño ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Gold Nanorods ◽  
Ligand Exchange ◽  
Cetyltrimethylammonium Bromide ◽  
Gold Nanorod ◽  
Experimental Conditions ◽  
Seed Mediated ◽  
The Stability

The highly packed cetyltrimethylammonium bromide bilayer on the surface of gold nanorods synthesized by the seed-mediated procedure hampers the complete ligand exchange under experimental conditions that preserves the stability of the dispersions.

scholarly journals The dependence of medium refractive index on optical properties of gold nanorods and their SERS application

AIP Advances ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 055319
Author(s):  
Do Thi Hue ◽  
Tran Thi Thu Huong ◽  
Pham Thi Thu Ha ◽  
Tran Thu Trang ◽  
Nghiem Thi Ha Lien ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Gold Nanorods
Sign in / Sign up

Export Citation Format

Share Document