Numerical investigation of the refractive index sensitivity of au/Ag core-shell nanostructures (for sensing applications)

We present a new type of localized surface plasmon resonance (LSPR) sensor whose refractive index sensitivity can be improved by greatly increasing the plasmon wavelength red-shift of metal–semiconductor core–shell nanoparticles (CSNs).

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Plasmonic coupling in Au, Ag and Al nanosphere homo-dimers for sensing and SERS

Advanced Electromagnetics ◽

10.7716/aem.v7i2.563 ◽

2018 ◽

Vol 7 (2) ◽

pp. 83-90 ◽

Cited By ~ 7

Author(s):

J. Katyal

Keyword(s):

Refractive Index ◽

Near Field ◽

Visible Region ◽

Field Enhancement ◽

Interparticle Spacing ◽

Localized Surface Plasmon ◽

Refractive Index Sensitivity ◽

Plasmonic Material ◽

Sensing Applications ◽

Index Sensitivity

The localized surface plasmon resonance of homo-dimer nanostructures is studied using FDTD simulations. The calculated LSPR wavelength of Au, Ag and Al nanosphere forming a homo-dimer configuration is compared and the results reveal a larger LSPR shift in Ag and Al homo-dimer than in Au homo-dimer. Taking the sensitivity of LSPR shape to the size and interparticle spacing of nanoparticle along with a surrounding refractive index, parameters like refractive index sensitivity have been determined. The spherical homo-dimer over the whole range of particle size, studied here shows the index sensitivity order as Ag>Al>Au. Hence, the use of plasmonic material towards the refractive index sensing applications is useful in this order. The average refractive index sensitivities of Ag, Al and Au are 287.09 nm/RIU, 210.21 nm/RIU and 192.47 nm/RIU in DUV-Visible-NIR region. Apart from LSPR shift, the highly confined near-field intensity enhancement of homo-dimer nanostructures for SERS has also been studied. The interacting homo-dimer nanoparticles reveals intensity enhancements in the junction. Comparing the field enhancement for Au, Ag and Al homo-dimer nanostructure 10^8-10^9 have been theoretically predicted in DUV-UV-visible region which can be used to strongly enhance the Raman scattering of molecules.

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Refractive index sensitivity of Au nanostructures in solution and on the substrate

Journal of Materials Science Materials in Electronics ◽

10.1007/s10854-021-07593-9 ◽

2021 ◽

Author(s):

Hemant Ramakant Hegde ◽

Santhosh Chidangil ◽

Rajeev K. Sinha

Keyword(s):

Refractive Index ◽

Colloidal Solution ◽

Synthesis Method ◽

Peak Position ◽

Localized Surface Plasmon ◽

Surface Immobilization ◽

Refractive Index Sensitivity ◽

Sensing Applications ◽

Sensing Platforms ◽

Index Sensitivity

AbstractIn this work, we present the synthesis and surface immobilization of Au nanostars, Au nanocubes and Au nanorods for localized surface plasmon resonance (LSPR)-based refractometric sensing applications. Au nanostructures exhibiting LSPR peak positions in 500–900 nm spectral range were prepared by seed-mediated synthesis method. The refractive index (RI) sensitivity of all these nanostructures in the colloidal solution were measured and the sample exhibiting highest sensitivity in each category were immobilized on the glass substrate. The surface immobilized nanostructures were investigated for RI sensing. Au nanostars having LSPR peak position at 767 nm exhibited highest RI sensitivity of 484 nm/RIU in solution and 318 nm/RIU on the substrate. This study gives an outline for selecting the Au nanostructures for developing plasmonic sensing platforms.

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(Gold triangular nanoplate core)@(silver shell) nanostructures as highly sensitive and selective plasmonic nanoprobes for hydrogen sulfide detection

Nanoscale ◽

10.1039/d0nr05728b ◽

2020 ◽

Vol 12 (39) ◽

pp. 20250-20257 ◽

Cited By ~ 1

Author(s):

Hua Mi ◽

Shengyan Wang ◽

Hang Yin ◽

Le Wang ◽

Lin Mei ◽

...

Keyword(s):

Refractive Index ◽

Hydrogen Sulfide ◽

High Refractive Index ◽

Great Sensitivity ◽

Refractive Index Sensitivity ◽

Shell Nanostructures ◽

Highly Sensitive ◽

Index Sensitivity ◽

Silver Shell

AuTNP@Ag nanostructures are developed as nanoprobes for hydrogen sulfide. Owing to the high refractive index sensitivity of Au TNPs and facile sulfurization of silver, AuTNP@Ag nanostructures exhibit great sensitivity to both sulfur ions and H2S gas.

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Controllable Preparation of Core–Shell Au–Ag Nanoshuttles with Improved Refractive Index Sensitivity and SERS Activity

ACS Applied Materials & Interfaces ◽

10.1021/am405357v ◽

2014 ◽

Vol 6 (5) ◽

pp. 3331-3340 ◽

Cited By ~ 51

Author(s):

Tingting Bai ◽

Jianfei Sun ◽

Renchao Che ◽

Lina Xu ◽

Chenyue Yin ◽

...

Keyword(s):

Refractive Index ◽

Core Shell ◽

Refractive Index Sensitivity ◽

Index Sensitivity ◽

Controllable Preparation

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Dewetting Metal Nanofilms—Effect of Substrate on Refractive Index Sensitivity of Nanoplasmonic Gold

Nanomaterials ◽

10.3390/nano9111530 ◽

2019 ◽

Vol 9 (11) ◽

pp. 1530 ◽

Cited By ~ 4

Author(s):

Nikhil Bhalla ◽

Aditya Jain ◽

Yoonjoo Lee ◽

Amy Q. Shen ◽

Doojin Lee

Keyword(s):

Refractive Index ◽

Localized Surface Plasmon ◽

Metal Nanostructures ◽

Refractive Index Sensitivity ◽

Ceramic Substrates ◽

Sensing Applications ◽

Wide Range ◽

Metal Nanostructure ◽

Index Sensitivity ◽

Silicon Based

The localized surface plasmon resonance (LSPR) sensitivity of metal nanostructures is strongly dependent on the interaction between the supporting substrate and the metal nanostructure, which may cause a change in the local refractive index of the metal nanostructure. Among various techniques used for the development of LSPR chip preparation, solid-state dewetting of nanofilms offers fast and cost effective methods to fabricate large areas of nanostructures on a given substrate. Most of the previous studies have focused on the effect of the size, shape, and inter-particle distance of the metal nanostructures on the LSPR sensitivity. In this work, we reveal that the silicon-based supporting substrate influences the LSPR associated refractive index sensitivity of gold (Au) nanostructures designed for sensing applications. Specifically, we develop Au nanostructures on four different silicon-based ceramic substrates (Si, SiO2, Si3N4, SiC) by thermal dewetting process and demonstrate that the dielectric properties of these ceramic substrates play a key role in the LSPR-based refractive index (RI) sensitivity of the Au nanostructures. Among these Si-supported Au plasmonic refractive index (RI) sensors, the Au nanostructures on the SiC substrates display the highest average RI sensitivity of 247.80 nm/RIU, for hemispherical Au nanostructures of similar shapes and sizes. Apart from the significance of this work towards RI sensing applications, our results can be advantageous for a wide range of applications where sensitive plasmonic substrates need to be incorporated in silicon based optoelectronic devices.

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High-sensitivity refractive index of Au@Cu2−xS core–shell nanorods

RSC Advances ◽

10.1039/c8ra07711h ◽

2018 ◽

Vol 8 (61) ◽

pp. 35005-35013 ◽

Cited By ~ 1

Author(s):

Pengfei Cao ◽

Huizhen Chen ◽

Hailong Zhang ◽

Lin Cheng ◽

Tiaoming Niu

Keyword(s):

Refractive Index ◽

Near Infrared ◽

High Sensitivity ◽

High Refractive Index ◽

Core Shell ◽

Refractive Index Sensitivity ◽

Index Sensitivity

A high refractive index sensitivity of Au@Cu2−xS core–shell nanorods working in the near-infrared is theoretically demonstrated.

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Improved Refractive Index Sensitivity Utilizing Long-Period Gratings with Periodic Corrugations on Cladding

Journal of Sensors ◽

10.1155/2012/483471 ◽

2012 ◽

Vol 2012 ◽

pp. 1-5 ◽

Cited By ~ 12

Author(s):

Anthony Lim ◽

Wen Bin Ji ◽

Swee Chuan Tjin

Keyword(s):

Refractive Index ◽

Cost Effective ◽

Experimental Results ◽

Refractive Index Sensitivity ◽

Long Period ◽

Specimen Collection ◽

Long Period Gratings ◽

Highly Sensitive ◽

Index Sensitivity

A new structure of Long-Period Gratings (LPGs) sensor is introduced as a sensitive ambient RI sensor. This structure consists of creating periodic corrugations on the cladding of the LPG. The experimental results show that this LPG structure has good performances in terms of linearity and sensitivity and serves as a highly sensitive and cost-effective sensor. It also has the advantage of portability as the corrugation can also serve as the reservoir for the specimen collection to be tested.

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The local surface plasmon resonance property and refractive index sensitivity of metal elliptical nano-ring arrays

AIP Advances ◽

10.1063/1.4901910 ◽

2014 ◽

Vol 4 (11) ◽

pp. 117115 ◽

Cited By ~ 1

Author(s):

Weihua Lin ◽

Qian Wang ◽

Qiuze Li ◽

Anhua Dong

Keyword(s):

Refractive Index ◽

Surface Plasmon Resonance ◽

Surface Plasmon ◽

Plasmon Resonance ◽

Local Surface ◽

Resonance Property ◽

Refractive Index Sensitivity ◽

Local Surface Plasmon Resonance ◽

Index Sensitivity

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Improve the Hole Size-dependent Refractive Index Sensitivity of Au-Ag Nanocages by Tuning the Alloy Composition

10.21203/rs.3.rs-482206/v1 ◽

2021 ◽

Author(s):

Jianjun LI ◽

Qiu-Xiang Qin ◽

Guo-Jun Weng ◽

Jian Zhu ◽

Jun-Wu Zhao

Keyword(s):

Dielectric Constant ◽

Refractive Index ◽

Electric Field ◽

Alloy Composition ◽

Geometric Parameters ◽

Sensitivity Factor ◽

Hole Size ◽

Refractive Index Sensitivity ◽

Electric Field Direction ◽

Index Sensitivity

Abstract In this study, the nanoboxes is converted into Au-Ag alloy nanocages by increasing the hole size. Discrete dipole approximation (DDA) is used to study the extinction spectrum and the refractive index sensing characteristics of Au-Ag alloy nanocages with different geometric parameters. With the increase of Au component, the local surface plasmon resonance (LSPR) peak shows approximately linear redshift and the sensitivity factor shows approximately linear decrease. The refractive index sensitivity can be effectively controlled by the Au-Ag ratio at large hole size because the hole and cavity surfaces distribute more environmental dielectric components. Therefore, increasing the hole size and decreasing the Au-Ag ratio can improve the refractive index sensitivity. To explain the effect of alloy composition on the LSPR characteristics and the refractive index sensitivity, the local electric field distributions with different geometric parameters are plotted. We find that the electric field direction on the hole and cavity surfaces are controlled by the Au-Ag ratio and environmental dielectric constant. Moreover, the field vector on the hole and cavity surfaces are formed by the superposition of the incident field, the electric field generated by the oscillating electrons on the outer surface, and the polarized field in the environmental dielectric constant.

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