scholarly journals Improving the Detection Accuracy of an Ag/Au Bimetallic Surface Plasmon Resonance Biosensor Based on Graphene

Chemosensors ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 10
Author(s):  
Qi Wang ◽  
Shuhua Cao ◽  
Xufeng Gao ◽  
Xinrui Chen ◽  
Dawei Zhang
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Bias Voltage ◽  
Plasmon Resonance ◽  
Chemical Potential ◽  
Detection Accuracy ◽  
Sensor Surface ◽  
Graphene Layers ◽  
Bimetallic Surface ◽  
Surface System

A theoretical study was conducted with the aim of improving the detection accuracy of graphene-based surface plasmon resonance (SPR) biosensors. We studied the effect of applying a bias voltage to the sensor surface on its detection accuracy. The optimum thicknesses of silver and gold layers in the biosensor of 47 nm and 3 nm, respectively, were determined. Graphene layers deposited on these thin silver and gold films formed a sensor surface system, on which the surface plasmons were excited. The real and imaginary parts of the refractive index of graphene were controlled by the bias voltage. When the chemical potential was increased from 36 meV to 8 eV, the detection accuracy of the sensor was correspondingly increased by 213%.

scholarly journals Sensitivity Analysis of Single- and Bimetallic Surface Plasmon Resonance Biosensors

Sensors ◽  
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.

scholarly journals Cellulose and Vanadium Plasmonic Sensor to Measure Ni2+ Ions

2021 ◽  
Vol 11 (7) ◽  
pp. 2963
Author(s):  
Nur Alia Sheh Omar ◽  
Yap Wing Fen ◽  
Irmawati Ramli ◽  
Umi Zulaikha Mohd Azmi ◽  
Hazwani Suhaila Hashim ◽  
...  
Keyword(s):  
Thin Film ◽  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Signal To Noise Ratio ◽  
Affinity Constant ◽  
Detection Accuracy ◽  
Plasmonic Sensor ◽  
Spr Sensor ◽  
Resonance Sensor

A novel vanadium–cellulose composite thin film-based on angular interrogation surface plasmon resonance (SPR) sensor for ppb-level detection of Ni(II) ion was developed. Experimental results show that the sensor has a linear response to the Ni(II) ion concentrations in the range of 2–50 ppb with a determination coefficient (R2) of 0.9910. This SPR sensor can attain a maximum sensitivity (0.068° ppb−1), binding affinity constant (1.819 × 106 M−1), detection accuracy (0.3034 degree−1), and signal-to-noise-ratio (0.0276) for Ni(II) ion detection. The optical properties of thin-film targeting Ni(II) ions in different concentrations were obtained by fitting the SPR reflectance curves using the WinSpall program. All in all, the proposed Au/MPA/V–CNCs–CTA thin-film-based surface plasmon resonance sensor exhibits better sensing performance than the previous film-based sensor and demonstrates a wide and promising technology candidate for environmental monitoring applications in the future.

The effect of graphene on surface plasmon resonance of metal nanoparticles

2018 ◽  
Vol 20 (38) ◽  
pp. 25078-25084 ◽  
Author(s):  
Haiyan Nan ◽  
Zhirong Chen ◽  
Jie Jiang ◽  
JiaQi Li ◽  
Weiwei Zhao ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
Metal Nanoparticles ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Localized Surface Plasmon Resonance ◽  
Metal Nanoparticle ◽  
Localized Surface Plasmon ◽  
Au Nps ◽  
Hybrid Schemes ◽  
Graphene Layers

Two transparent graphene–metal nanoparticle (NP) hybrid schemes, namely Au NPs covered by graphene layers and Au NPs encapsulated by graphene layers, are presented and the effect of graphene on the localized surface plasmon resonance of metal NPs is systematically investigated.

Sensitivity Parameter Analysis of Graphene Based Bimetallic Surface Plasmon Resonance Biosensor

2015 ◽  
Vol 34 ◽  
pp. 17-21 ◽  
Author(s):  
Goutam Mohanty ◽  
Bijay Kumar Sahoo ◽  
Jamil Akhtar
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Computational Simulation ◽  
Adhesive Layer ◽  
Parameter Analysis ◽  
Silver Layer ◽  
Bimetallic Surface ◽  
Spr Biosensor ◽  
Bk7 Glass

In this paper, we have studied theoretically the effect of bimetallic silver/ gold layer on sensitivity of the graphene based surface plasmon resonance (SPR) biosensor. Here, silver layer (instead of chromium and titanium) is used as an adhesive layer in between gold and BK7 glass prism. The optimized thickness of silver/gold layers reported in literature has been used for the analysis of various sensitivity parameters of the biosensor. A computational simulation is performed to analyze the nature of plasmon dip shift with respect to the addition of graphene layer and binding layer respectively.

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

Biosensors ◽  
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.

scholarly journals Magneto-Optic Surface Plasmon Resonance Ti/Au/Co/Au/Pc Configuration and Sensitivity

2018 ◽  
Author(s):  
Conrad Rizal
Keyword(s):  
Magnetic Field ◽  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Protective Layer ◽  
Surface Cleaning ◽  
Water Medium ◽  
Sensor Surface ◽  
X Ray ◽  
Magneto Optic

Magneto-optic surface plasmon resonance (MOSPR) based sensors are highly attractive as next generation biosensors. However, these sensors suffer from oxidation leading to degradation of performance, reproducibility of the sensor surface because of the difficulty of removing adsorbed materials, and degradation of sensor surface during surface cleaning, and these limit their applications. In this paper, I propose MOSPR-based biosensors with 0 to 15 nm thick inert polycarbonate laminate plastic as a protective layer and theoretically demonstrate the practicability of our approach in water-medium for three different probing samples: ethanol, propanol, and pentanol. I also investigate microstructure and magnetic properties. The chemical composition and layered information of the sensor are investigated using X-ray reflectivity and X-ray diffraction analyses and these show distinct fcc-Au (111) phases, as dominated by the higher density of conduction electrons in Au as compared to Co. The magnetic characterization measured with the in-plane magnetic field to the sensor surface for both the as-deposited and annealed multilayers showed isotropic easy axis magnetization parallel to the multilayer interface at a saturating magnetic field of <100 Oe. The sensor showed a maximum sensitivity of 5.5 × 104%/RIU for water-ethanol media and the highest detection level of 2.5 × 10−8 for water-pentanol media as the protective layer is increased from 0 to 15 nm.c

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