Surface Plasmon Resonance-Based Sensor Modeling

Exceptional optical and electrical characteristics of graphene based materials attract significant interest of the researchers to develop sensing center of surface Plasmon resonance (SPR) based sensors by graphene application. On the other hand refractive index calculation of graphene based structures is necessary for SPR sensor analysis. In this chapter first of all a new method for refractive index investigation of some graphene based structures are introduced and then the effect of carrier density variant in the form of conductance gradient on graphene based SPR sensor response is modeled. The molecular properties such as electro-negativity, molecular mass, effective group number and effective outer shell factor of the molecule are engaged. In addition each factor effect in the cumulative carrier variation is explored analytically. The refractive index shift equation based on these factors is defined and related coefficients are proposed. Finally a semi-empirical model for interpretation of changes in SPR curve is suggested and tested for some organic molecules.

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Numerical Study of Graphene/Au/SiC Waveguide-Based Surface Plasmon Resonance Sensor

Biosensors ◽

10.3390/bios11110455 ◽

2021 ◽

Vol 11 (11) ◽

pp. 455

Author(s):

Wei Du ◽

Lucas Miller ◽

Feng Zhao

Keyword(s):

Refractive Index ◽

Surface Plasmon Resonance ◽

Surface Plasmon ◽

Plasmon Resonance ◽

Disease Diagnosis ◽

Bandgap Energy ◽

Graphene Layers ◽

Spr Sensor ◽

Sensing Applications ◽

Resonance Sensor

A new waveguide-based surface plasmon resonance (SPR) sensor was proposed and investigated by numerical simulation. The sensor consists of a graphene cover layer, a gold (Au) thin film, and a silicon carbide (SiC) waveguide layer on a silicon dioxide/silicon (SiO2/Si) substrate. The large bandgap energy of SiC allows the sensor to operate in the visible and near-infrared wavelength ranges, which effectively reduces the light absorption in water to improve the sensitivity. The sensor was characterized by comparing the shift of the resonance wavelength peak with change of the refractive index (RI), which mimics the change of analyte concentration in the sensing medium. The study showed that in the RI range of 1.33~1.36, the sensitivity was improved when the graphene layers were increased. With 10 graphene layers, a sensitivity of 2810 nm/RIU (refractive index unit) was achieved, corresponding to a 39.1% improvement in sensitivity compared to the Au/SiC sensor without graphene. These results demonstrate that the graphene/Au/SiC waveguide SPR sensor has a promising use in portable biosensors for chemical and biological sensing applications, such as detection of water contaminations (RI = 1.33~1.34), hepatitis B virus (HBV), and glucose (RI = 1.34~1.35), and plasma and white blood cells (RI = 1.35~1.36) for human health and disease diagnosis.

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Numerical Investigation of the Microstructured Optical Fiber-Based Surface Plasmon Resonance Sensor with Silver Nanolayer

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.411-414.1573 ◽

2013 ◽

Vol 411-414 ◽

pp. 1573-1576 ◽

Cited By ~ 3

Author(s):

Nan Nan Luan ◽

Jian Quan Yao ◽

Ran Wang ◽

Cong Jing Hao ◽

Bao Qun Wu ◽

...

Keyword(s):

Refractive Index ◽

Surface Plasmon Resonance ◽

Optical Fiber ◽

Surface Plasmon ◽

Plasmon Resonance ◽

Silver Layer ◽

Spr Sensor ◽

Microstructured Optical Fiber ◽

Sensor Structure ◽

Resonance Sensor

The surface plasmon resonance (SPR) sensor is proposed based on coating the inner surfaces of an index-guiding microstructured optical fiber (MOF) with a silver layer. Fiber core is surrounded by six large metallized holes which should facilitate the fabrication of the layered sensor structure and the infiltration of the analyte. The relationship between the sensitivity of SPR sensor and the refractive index of MOF material is demonstrated with finite element method (FEM). Numerical simulation results indicate that the sensitivity of SPR sensor decreases as the refractive index of the MOF material increasing and both spectral and intensity sensitivity are estimated to be 6.25×10-5and 6.67×10-5with low refractive index of MOF materialn=1.46.

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Numerical study of a highly sensitive surface plasmon resonance sensor based on circular-lattice holey fiber

Chinese Physics B ◽

10.1088/1674-1056/ac43a5 ◽

2021 ◽

Author(s):

Jian-Fei Liao ◽

Dao-Ming Lu ◽

Li-Jun Chen ◽

Tian-Ye Huang

Keyword(s):

Refractive Index ◽

Surface Plasmon Resonance ◽

Surface Plasmon ◽

Plasmon Resonance ◽

Numerical Study ◽

Holey Fiber ◽

Spr Sensor ◽

Study Results ◽

Resonance Sensor ◽

Sensing Performance

Abstract A new design of surface plasmon resonance (SPR) sensor employing circular-lattice holey fiber to achieve high-sensitivity detection is proposed. The sensing performance of the proposed sensor is numerically investigated and the study results indicate that our proposed SPR sensor can be applied to the near-mid infrared detection. Moreover, the maximum wavelength sensitivity of our proposed sensor can reach as high as 1.76×104 nm/refractive index unit (RIU) and the maximum wavelength interrogation resolution can be up to 5.68×10-6 RIU when the refractive index (RI) of analyte lies in (1.31, 1.36). Thanks to its excellent sensing performance, our proposed SPR sensor will have great potential applications for biological analytes detection, food safety control, bio-molecules detection and so on.

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Surface Plasmon Resonance Sensor of CO2 for Indoors and Outdoors

Applied Sciences ◽

10.3390/app11156869 ◽

2021 ◽

Vol 11 (15) ◽

pp. 6869

Author(s):

Francisco Pérez-Ocón ◽

Antonio M. Pozo ◽

Jorge Cortina ◽

Ovidio Rabaza

Keyword(s):

Carbon Dioxide ◽

Refractive Index ◽

Surface Plasmon Resonance ◽

Surface Plasmon ◽

Plasmon Resonance ◽

Human Life ◽

Surface Plasmon Resonance Sensor ◽

Great Precision ◽

Spr Sensor ◽

Resonance Sensor

The ability to detect CO2 with the smallest possible devices, equipped with alarms and having great precision, is vital for human life, whether indoors or outdoors. It is essential to know if we are being subjected to this gas to establish the level of ventilation in factories, houses, classrooms, etc., and to be protected against viruses or dangerous gas concentrations. Equally, when we are in the countryside, it is useful to be able to evaluate if the greenhouse effect, caused by this gas, is increasing. We propose a surface plasmon resonance (SPR) sensor for the measurement of CO2 concentrations taking into account that the refractive index of carbon dioxide depends on temperature, humidity, pressure, etc. With our sensor we can measure (in air) in any type of environment and concentration. Our sensor has a resolution of 5.15 × 10−5 RIU and a sensitivity of 19.4 RIU−1 for 400 ppm.

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

Photonics ◽

10.3390/photonics8020041 ◽

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.

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

Nanomaterials ◽

10.3390/nano11071728 ◽

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.

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Microstructured Surface Plasmon Resonance Sensor Based on Inkjet 3D Printing Using Photocurable Resins with Tailored Refractive Index

Polymers ◽

10.3390/polym13152518 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2518

Author(s):

Nunzio Cennamo ◽

Lorena Saitta ◽

Claudio Tosto ◽

Francesco Arcadio ◽

Luigi Zeni ◽

...

Keyword(s):

Surface Plasmon Resonance ◽

3D Printing ◽

Surface Plasmon ◽

Plasmon Resonance ◽

Optical Sensor ◽

Low Cost ◽

3D Print ◽

Spr Sensor ◽

Resonance Sensor ◽

3D Printed

In this work, a novel approach to realize a plasmonic sensor is presented. The proposed optical sensor device is designed, manufactured, and experimentally tested. Two photo-curable resins are used to 3D print a surface plasmon resonance (SPR) sensor. Both numerical and experimental analyses are presented in the paper. The numerical and experimental results confirm that the 3D printed SPR sensor presents performances, in term of figure of merit (FOM), very similar to other SPR sensors made using plastic optical fibers (POFs). For the 3D printed sensor, the measured FOM is 13.6 versus 13.4 for the SPR-POF configuration. The cost analysis shows that the 3D printed SPR sensor can be manufactured at low cost (∼15 €) that is competitive with traditional sensors. The approach presented here allows to realize an innovative SPR sensor showing low-cost, 3D-printing manufacturing free design and the feasibility to be integrated with other optical devices on the same plastic planar support, thus opening undisclosed future for the optical sensor systems.

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An Enhanced Plastic Optical Fiber-Based Surface Plasmon Resonance Sensor with a Double-Sided Polished Structure

Sensors ◽

10.3390/s21041516 ◽

2021 ◽

Vol 21 (4) ◽

pp. 1516

Author(s):

Lian Liu ◽

Shijie Deng ◽

Jie Zheng ◽

Libo Yuan ◽

Hongchang Deng ◽

...

Keyword(s):

Surface Plasmon Resonance ◽

Optical Fiber ◽

Surface Plasmon ◽

Plasmon Resonance ◽

Low Cost ◽

Fiber Axis ◽

Plastic Optical Fiber ◽

Au Film ◽

Spr Sensor ◽

Resonance Sensor

An enhanced plastic optical fiber (POF)-based surface plasmon resonance (SPR) sensor is proposed by employing a double-sided polished structure. The sensor is fabricated by polishing two sides of the POF symmetrically along with the fiber axis, and a layer of Au film is deposited on each side of the polished region. The SPR can be excited on both polished surfaces with Au film coating, and the number of light reflections will be increased by using this structure. The simulation and experimental results show that the proposed sensor has an enhanced SPR effect. The visibility and full width at half maximum (FWHM) of spectrum can be improved for the high measured refractive index (RI). A sensitivity of 4284.8 nm/RIU is obtained for the double-sided POF-based SPR sensor when the measured liquid RI is 1.42. The proposed SPR sensor is easy fabrication and low cost, which can provide a larger measurement range and action area to the measured samples, and it has potential application prospects in the oil industry and biochemical sensing fields.

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Sensitivity Analysis of Single- and Bimetallic Surface Plasmon Resonance Biosensors

Sensors ◽

10.3390/s21134348 ◽

2021 ◽

Vol 21 (13) ◽

pp. 4348

Author(s):

Piotr Mrozek ◽

Ewa Gorodkiewicz ◽

Paweł Falkowski ◽

Bogusław Hościło

Keyword(s):

Refractive Index ◽

Surface Plasmon Resonance ◽

Surface Plasmon ◽

Plasmon Resonance ◽

Real Life ◽

Reflectance Measurement ◽

Near Surface ◽

Bimetallic Surface ◽

Calibration Curves ◽

Surface Sensing

Comparative analysis of the sensitivity of two surface plasmon resonance (SPR) biosensors was conducted on a single-metallic Au sensor and bimetallic Ag–Au sensor, using a cathepsin S sensor as an example. Numerically modeled resonance curves of Au and Ag–Au layers, with parameters verified by the results of experimental reflectance measurement of real-life systems, were used for the analysis of these sensors. Mutual relationships were determined between ∂Y/∂n components of sensitivity of the Y signal in the SPR measurement to change the refractive index n of the near-surface sensing layer and ∂n/∂c sensitivity of refractive index n to change the analyte’s concentration, c, for both types of sensors. Obtained results were related to experimentally determined calibration curves of both sensors. A characteristic feature arising from the comparison of calibration curves is the similar level of Au and Ag–Au biosensors’ sensitivity in the linear range, where the signal of the AgAu sensor is at a level several times greater. It was shown that the influence of sensing surface morphology on the ∂n/∂c sensitivity component had to be incorporated to explain the features of calibration curves of sensors. The shape of the sensory surface relief was proposed to increase the sensor sensitivity at low analyte concentrations.

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