scholarly journals Optical Properties and Instrumental Performance of thin Noble Metal (Cu, Au, Ag) Films Near the Surface Plasmon Resonance

2016 ◽  
Vol 168 ◽  
pp. 834-837 ◽  
Author(s):  
L.C. Oliveira ◽  
C.S. Moreira ◽  
H. Neff ◽  
A.M.N. Lima
Keyword(s):  
Optical Properties ◽  
Surface Plasmon Resonance ◽  
Noble Metal ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Instrumental Performance

scholarly journals Au Nanobipyramids with Pt decoration enveloped in TiO2 nanoboxes for photocatalytic reaction

2021 ◽  
Author(s):  
Weijian Gao ◽  
Caixia Kan ◽  
Shanlin Ke ◽  
Qinru Yun ◽  
Xingzhong Zhu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Surface Plasmon Resonance ◽  
Noble Metal ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Core Shell ◽  
Photocatalytic Reaction ◽  
Metal Nanocrystals ◽  
The Core

Noble metal nanocrystals and the core-shell nanocomposites have attracted particular interest due to their unique optical properties originated from the surface plasmon resonance (SPR) and wide applications related to the...

Optical properties and instrumental performance of thin gold films near the surface plasmon resonance

2006 ◽  
Vol 496 (2) ◽  
pp. 688-697 ◽  
Author(s):  
H. Neff ◽  
W. Zong ◽  
A.M.N. Lima ◽  
M. Borre ◽  
G. Holzhüter
Keyword(s):  
Optical Properties ◽  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Gold Films ◽  
Instrumental Performance

scholarly journals Optical Characterization of Ultra-Thin Films of Azo-Dye-Doped Polymers Using Ellipsometry and Surface Plasmon Resonance Spectroscopy

Photonics ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 41
Author(s):  
Najat Andam ◽  
Siham Refki ◽  
Hidekazu Ishitobi ◽  
Yasushi Inouye ◽  
Zouheir Sekkat
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Spectroscopic Ellipsometry ◽  
Plasmon Resonance ◽  
Complex Refractive Index ◽  
Resonance Spectroscopy ◽  
Doped Polymers

The determination of optical constants (i.e., real and imaginary parts of the complex refractive index (nc) and thickness (d)) of ultrathin films is often required in photonics. It may be done by using, for example, surface plasmon resonance (SPR) spectroscopy combined with either profilometry or atomic force microscopy (AFM). SPR yields the optical thickness (i.e., the product of nc and d) of the film, while profilometry and AFM yield its thickness, thereby allowing for the separate determination of nc and d. In this paper, we use SPR and profilometry to determine the complex refractive index of very thin (i.e., 58 nm) films of dye-doped polymers at different dye/polymer concentrations (a feature which constitutes the originality of this work), and we compare the SPR results with those obtained by using spectroscopic ellipsometry measurements performed on the same samples. To determine the optical properties of our film samples by ellipsometry, we used, for the theoretical fits to experimental data, Bruggeman’s effective medium model for the dye/polymer, assumed as a composite material, and the Lorentz model for dye absorption. We found an excellent agreement between the results obtained by SPR and ellipsometry, confirming that SPR is appropriate for measuring the optical properties of very thin coatings at a single light frequency, given that it is simpler in operation and data analysis than spectroscopic ellipsometry.

scholarly journals Numerical Study on the Surface Plasmon Resonance Tunability of Spherical and Non-Spherical Core-Shell Dimer Nanostructures

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1728
Author(s):  
Joshua Fernandes ◽  
Sangmo Kang
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Surface Plasmon Resonance ◽  
Aspect Ratio ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Shell Thickness ◽  
Numerical Study ◽  
Field Enhancement ◽  
Core Shell

The near-field enhancement and localized surface plasmon resonance (LSPR) on the core-shell noble metal nanostructure surfaces are widely studied for various biomedical applications. However, the study of the optical properties of new plasmonic non-spherical nanostructures is less explored. This numerical study quantifies the optical properties of spherical and non-spherical (prolate and oblate) dimer nanostructures by introducing finite element modelling in COMSOL Multiphysics. The surface plasmon resonance peaks of gold nanostructures should be understood and controlled for use in biological applications such as photothermal therapy and drug delivery. In this study, we find that non-spherical prolate and oblate gold dimers give excellent tunability in a wide range of biological windows. The electromagnetic field enhancement and surface plasmon resonance peak can be tuned by varying the aspect ratio of non-spherical nanostructures, the refractive index of the surrounding medium, shell thickness, and the distance of separation between nanostructures. The absorption spectra exhibit considerably greater dependency on the aspect ratio and refractive index than the shell thickness and separation distance. These results may be essential for applying the spherical and non-spherical nanostructures to various absorption-based applications.

Graphene–noble metal bilayers for inverted surface plasmon resonance biosensors

2013 ◽  
Vol 15 (5) ◽  
pp. 055010 ◽  
Author(s):  
P Zuppella ◽  
S Tosatto ◽  
A J Corso ◽  
S Zuccon ◽  
M G Pelizzo
Keyword(s):  
Surface Plasmon Resonance ◽  
Noble Metal ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Metal Bilayers

Bimetallic structures to enhance the performance of surface plasmon resonance sensors

2021 ◽  
Author(s):  
◽  
Roshni Satheesh Babu
Keyword(s):  
Surface Plasmon Resonance ◽  
Noble Metal ◽  
Surface Plasmon ◽  
Chemical Stability ◽  
Plasmon Resonance ◽  
Single Layer ◽  
Sensor Chip ◽  
Laser Source ◽  
Capping Layer ◽  
Enhanced Sensitivity

<p><b>Surface plasmon resonance (SPR) sensing is a label−free and rapid detection method and has extensive applications in the field of medical diagnostics, food control, and environmental monitoring. However, the lack of sensitivity to detect small molecules is a continuing concern in the application of this technique. Past research has explored different plasmonic structures such as metal nanoparticles, metallic nanoslits, nanoholes, colloidal Au nanoparticles, 2D nanomaterials, and multilayer structures as the sensing layer to improve the sensitivity of these sensors. However, the sensitivity improvement could be realised only with the cost of the increased complexity of optical configuration and sensor chip fabrication. Silver (Ag) is a very good candidate as the metallic layer for the sensor chip due to its higher electrical conductivity as compared to gold (Au). Besides cost−effectiveness, Ag thin film based sensors have better sensitivity with a sharp resonance dip and a high signal−to−noise ratio. However, the poor chemical stability of Ag thin films prevents their use in practical applications. Noble metals such as Au and platinum (Pt) offer greatly enhanced chemical stability. This work investigated the development of SPR sensors composed of a silver−noble metal bilayer structure to utilize both the sensitivity of silver and the chemical stability of the noble metal.</b></p> <p>To enable this research, an automated experimental SPR testbed for sensor characterisation was designed and constructed. This testbed is based on the Kretschmann configuration, using a He−Ne laser source at 632.8 nm. SPR sensor consisting of multilayer metal structures was fabricated using standard microelectronic fabrication techniques.</p> <p>The influence of the relative thickness of a noble metal capping layer on the SPR response and sensitivity from the Ag layer was systematically optimised, using both theoretical and experimental approaches. A theoretical analysis of the performance of the bimetallic SPR sensors was done using the transfer matrix method (TMM) by assuming a five−layer configuration. In the case of an Au capping layer, these simulations indicate an optimised thickness of 45 nm for Ag and 5 nm for Au. The observation from experimental analysis of different thickness combinations of Ag and Au matched the simulated results. However, the results of the stability studies exclude the practical use of 45 nm Ag/5 nm Au structures, as long−term degradation of the Ag layer occurs. A structure of 40 nm Ag/10nm Au was thus selected as the best composition for sensor applications. It is showed that sensors fabricated with this structure showed enhanced sensitivity compared to single−layer Au sensors, with a sensitivity 50% higher than that of the single−layer Au sensor. In the case of Ag/Pt structures, simulations indicated enhanced sensitivity from a 10 nm Ag/16 nm Pt structure. However, experimental measurements did not show any evidence for SPP excitation of Pt at the measured wavelength of 632.8 nm, making it unsuitable as a capping layer in our studies.</p> <p>The application of 40 nm Ag/10 nm Au bimetal layers as biosensors was done by the immobilization of thiol−terminated vitamin B12 aptamers on the Au sensor surface. However, the results were not reproducible, and more work on the binding kinetics of this aptamer will need to be performed to use this in a biosensor structure.</p>

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