Comparative analysis for reflectivity of graphene based SPR biosensor

Mohanty, Goutam; Sahoo, Bijay Kumar; Akhtar, Jamil

doi:10.1007/s11082-014-0057-2

Cited by 15 publications

(15 citation statements)

References 13 publications

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“…However, the calculated values are less than half of the lowest experimental value [15,[40][41][42]. The predicted shift of ~0.1 degree is always reached when graphene is treated as a 0.34-nm thick flat homogeneous film with a refractive index of ~2.95+1.54i, which is an in-plane index obtained by ellipsometry [22,[32][33][34][35][36][37][38]. The same SPR shift is obtained for our three types of Au films if we follow the same modelling approach.…”

Section: Resultssupporting

confidence: 71%

“…Graphene induced SPR shift has also been calculated by many groups [32][33][34][35][36][37][38]. However, the calculated values are less than half of the lowest experimental value [15,[40][41][42].…”

Section: Resultsmentioning

confidence: 98%

“…It is important to point out that graphene is still quite flat (Fig. 4b), it is also anisotropic, although it has been treated as an isotropic medium in previous calculations of SPR shift [32][33][34][35][36][37][38]. The effective dielectric constant can be conveniently derived based on its definition and Maxwell equation's boundary conditions: ɛ eff is the ratio of average electric flux density, D, to average electric field, E; E is continuous in parallel direction) and D is continuous in perpendicular direction [3].…”

Section: − −1 +2mentioning

confidence: 99%

“…However, there has been a big discrepancy between theory and experiment. Based on the flat graphene picture, the SPR shift of an Au film in resonant angle with and without single layer graphene in air is calculated to be less than 0.1 degree [32][33][34][35][36][37][38].…”

Section: Introductionmentioning

confidence: 99%

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Large graphene-induced shift of surface-plasmon resonances of gold films: Effective-medium theory for atomically thin materials

Alam

Niu

Wang

et al. 2020

Phys. Rev. Research

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Despite successful modeling of graphene as a 0.34-nm thick optical film synthesized by exfoliation or chemical vapor deposition (CVD), graphene induced shift of surface plasmon resonance (SPR) of gold films has remained controversial. Here we report the resolution of this controversy by developing a clean CVD graphene transfer method and extending Maxwell-Garnet effective medium theory (EMT) to 2D materials. A SPR shift of 0.24º is obtained and it agrees well with 2D EMT in which wrinkled graphene is treated as a 3-nm graphene/air layered composite, in agreement with the average roughness measured by atomic force microscope. Because the anisotropic built-in boundary condition of 2D EMT is compatible with graphene's optical anisotropy, graphene can be modelled as a film thicker than 0.34-nm without changing its optical property; however, its actual roughness, i.e., effective thickness will significantly alter its response to strong out-of-plane fields, leading to a larger SPR shift.

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Section: Resultssupporting

confidence: 71%

Section: Resultsmentioning

confidence: 98%

Section: − −1 +2mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Large graphene-induced shift of surface-plasmon resonances of gold films: Effective-medium theory for atomically thin materials

Alam

Niu

Wang

et al. 2020

Phys. Rev. Research

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“…As a result, the propagation constant can be optically measured in terms of reflection co-efficient. The reflectance co-efficient of N-layer system for p-polarized light is [12,21,24]:…”

Section: Theory and Principlementioning

confidence: 99%

Effect of Semiconductor on Sensitivity of a Graphene-Based Surface Plasmon Resonance Biosensor

2015

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In this theoretical study, the effect of semiconductor on sensitivity of a graphene-based surface plasmon resonance (SPR) biosensor has been presented. Different semiconductors such as silicon (Si), germanium (Ge) and wurtzite III-V nitrides (AlN, GaN and InN) have been placed in between active silver (Ag) metal and graphene layer. Our simulation result shows that addition of semiconductor layer enhances the sensitivity by a factor of 3.76, 2.19, 3.82, 3.94 and 4.17 respectively for Si, Ge, InN, GaN and AlN. Also, we have examined the field enhancement factor due to above semiconductors and found maximum field intensity enhancement for the case of AlN. The analysis shows that best performance is achieved for red He-Ne laser light when optimized thicknesses of silver, AlN and graphene layer are 55, 14 and 0.34 nm (monolayer of graphene), respectively. More specifically, AlN would be a better choice for biosensing application in SPR biosensor.

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Tools for detecting insect semiochemicals: a review

et al. 2018

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Semiochemicals are chemical compounds that are released by many species as a means of intra- and interspecific communication. Insects have extremely advanced olfactory systems; indeed, they rely on smell when performing many of their main behaviors, such as oviposition, breeding, prey location, and defense. This characteristic of insects implies that semiochemicals could be used for various applications, including in agriculture, where they could be employed along with other tools to control pest insects. The aim of this review is to present the main techniques used and the state of the art in the detection of semiochemicals, focusing on pheromones. In addition to the traditional methods of identifying semiochemicals, such as gas chromatography coupled to a high-resolution detection mode (e.g., flame ionization (FID), electron capture (ECD), photoionization (PID), or mass spectrometry (MS)), other tools are addressed in this review, including sensors and biosensors. While these new technologies may be used under laboratory conditions to improve or complement technologies that are already being used, they are mainly intended for use as new agricultural tools for detecting and controlling pest insects in the field.

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Comparative analysis for reflectivity of graphene based SPR biosensor

Cited by 15 publications

References 13 publications

Large graphene-induced shift of surface-plasmon resonances of gold films: Effective-medium theory for atomically thin materials

Large graphene-induced shift of surface-plasmon resonances of gold films: Effective-medium theory for atomically thin materials

Effect of Semiconductor on Sensitivity of a Graphene-Based Surface Plasmon Resonance Biosensor

Tools for detecting insect semiochemicals: a review

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