Influence of shell thickness on the refractive index sensitivity of localized surface plasmon resonance inflection points in silver-coated gold nanorods

The nano-thick-dielectric encapsulation effects on the bulk and local refractive index sensitivity behaviors of Ag plane-nanosphere-cluster sensors (including nanosphere monomers, dimers, trimer chains and trimer equilateral triangles, four kinds of normally encountered nanoparticles in experiments) have been numerically investigated by finite element method (FEM). The encapsulation is revealed to decrease the quadratic magnitude of the refractive index responses of their peak wavelengths of localized surface plasmon resonances (LSPR), while it does not violate such quadratic response natures. Its effect on their capabilities of surface enhanced Raman scattering (SERS) behaviors is discussed too. It is demonstrated to provide an efficient type of SERS substrate for plasmonic sensing and detections, which improves the stability of the concerned nanoparticles, and not diminish their SERS signals, in agreement well with experiments under the same nanostructure parameters. This work holds great promise for further designing SERS-based sensing/detecting substrates and sensors/detectors.

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Double-exponential refractive index sensitivity of metal–semiconductor core–shell nanoparticles: the effects of dual-plasmon resonances and red-shift

RSC Advances ◽

10.1039/c7ra11981j ◽

2018 ◽

Vol 8 (3) ◽

pp. 1700-1705 ◽

Cited By ~ 7

Author(s):

Hailong Zhang ◽

Pengfei Cao ◽

Jie Dou ◽

Lin Cheng ◽

Tiaoming Niu ◽

...

Keyword(s):

Refractive Index ◽

Red Shift ◽

Localized Surface Plasmon ◽

Core Shell ◽

Refractive Index Sensitivity ◽

Shell Nanoparticles ◽

Double Exponential ◽

New Type ◽

Index Sensitivity ◽

Core Shell Nanoparticles

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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Refractive Index Sensitivity and SERS Ability of Citrate versus CTAB-Stabilized Gold Nanorods: A Comparative Study

Nanoscience and Nanotechnology Letters ◽

10.1166/nnl.2018.2584 ◽

2018 ◽

Vol 10 (1) ◽

pp. 119-126 ◽

Cited By ~ 1

Author(s):

Kangzhen Zhang ◽

Tingting Bai ◽

Meng Wang ◽

Yuntao Li ◽

Xiang Lu ◽

...

Keyword(s):

Refractive Index ◽

Comparative Study ◽

Gold Nanorods ◽

Refractive Index Sensitivity ◽

Index Sensitivity

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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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