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Narrow groove plasmonic nano-gratings for surface plasmon resonance sensing.

Dhawan A, Canva M, Vo-Dinh T - Opt Express (2011)

Bottom Line: We present a novel surface plasmon resonance (SPR) configuration based on narrow groove (sub-15 nm) plasmonic nano-gratings such that normally incident radiation can be coupled into surface plasmons without the use of prism-coupling based total internal reflection, as in the classical Kretschmann configuration.Our calculations indicate substantially higher differential reflectance signals, on localized change of refractive index in the narrow groove plasmonic gratings, as compared to those obtained from conventional SPR-based sensing systems.Furthermore, these calculations allow determination of the optimal nano-grating geometric parameters - i. e. nanoline periodicity, spacing between the nanolines, as well as the height of the nanolines in the nano-grating - for highest sensitivity to localized change of refractive index, as would occur due to binding of a biomolecule target to a functionalized nano-grating surface.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA.

ABSTRACT
We present a novel surface plasmon resonance (SPR) configuration based on narrow groove (sub-15 nm) plasmonic nano-gratings such that normally incident radiation can be coupled into surface plasmons without the use of prism-coupling based total internal reflection, as in the classical Kretschmann configuration. This eliminates the angular dependence requirements of SPR-based sensing and allows development of robust miniaturized SPR sensors. Simulations based on Rigorous Coupled Wave Analysis (RCWA) were carried out to numerically calculate the reflectance - from different gold and silver nano-grating structures - as a function of the localized refractive index of the media around the SPR nano-gratings as well as the incident radiation wavelength and angle of incidence. Our calculations indicate substantially higher differential reflectance signals, on localized change of refractive index in the narrow groove plasmonic gratings, as compared to those obtained from conventional SPR-based sensing systems. Furthermore, these calculations allow determination of the optimal nano-grating geometric parameters - i. e. nanoline periodicity, spacing between the nanolines, as well as the height of the nanolines in the nano-grating - for highest sensitivity to localized change of refractive index, as would occur due to binding of a biomolecule target to a functionalized nano-grating surface.

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Related in: MedlinePlus

(a) RCWA calculations showing the effect of angle of incidence on reflectance - the wavelength of the incident radiation being the plasmon resonance wavelength for the gold (761 nm) and silver (702 nm) nanolines grating structures. The nano-grating height ‘H’ and periodicity ‘P’ are 100 nm, the spacing ‘W’ between the nanolines is 7 nm, and the refractive index of the medium surrounding the nano-grating is 1.33. (b) RCWA calculations showing the reflectance spectra from nanolines grating structures of different materials, for normally incident radiation on these nano-gratings. For all nano-grating materials, the nano-grating height ‘H’ and periodicity ‘P’ are 100 nm, the spacing ‘W’ between the nanolines is 7 nm, and the refractive index of the medium surrounding the nano-grating is 1.33.
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g008: (a) RCWA calculations showing the effect of angle of incidence on reflectance - the wavelength of the incident radiation being the plasmon resonance wavelength for the gold (761 nm) and silver (702 nm) nanolines grating structures. The nano-grating height ‘H’ and periodicity ‘P’ are 100 nm, the spacing ‘W’ between the nanolines is 7 nm, and the refractive index of the medium surrounding the nano-grating is 1.33. (b) RCWA calculations showing the reflectance spectra from nanolines grating structures of different materials, for normally incident radiation on these nano-gratings. For all nano-grating materials, the nano-grating height ‘H’ and periodicity ‘P’ are 100 nm, the spacing ‘W’ between the nanolines is 7 nm, and the refractive index of the medium surrounding the nano-grating is 1.33.

Mentions: In this paper, we have also discussed how normally incident radiation can be coupled into surface plasmons using the narrow groove plasmonic nano-gratings. Figure 8aFig. 8


Narrow groove plasmonic nano-gratings for surface plasmon resonance sensing.

Dhawan A, Canva M, Vo-Dinh T - Opt Express (2011)

(a) RCWA calculations showing the effect of angle of incidence on reflectance - the wavelength of the incident radiation being the plasmon resonance wavelength for the gold (761 nm) and silver (702 nm) nanolines grating structures. The nano-grating height ‘H’ and periodicity ‘P’ are 100 nm, the spacing ‘W’ between the nanolines is 7 nm, and the refractive index of the medium surrounding the nano-grating is 1.33. (b) RCWA calculations showing the reflectance spectra from nanolines grating structures of different materials, for normally incident radiation on these nano-gratings. For all nano-grating materials, the nano-grating height ‘H’ and periodicity ‘P’ are 100 nm, the spacing ‘W’ between the nanolines is 7 nm, and the refractive index of the medium surrounding the nano-grating is 1.33.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3368305&req=5

g008: (a) RCWA calculations showing the effect of angle of incidence on reflectance - the wavelength of the incident radiation being the plasmon resonance wavelength for the gold (761 nm) and silver (702 nm) nanolines grating structures. The nano-grating height ‘H’ and periodicity ‘P’ are 100 nm, the spacing ‘W’ between the nanolines is 7 nm, and the refractive index of the medium surrounding the nano-grating is 1.33. (b) RCWA calculations showing the reflectance spectra from nanolines grating structures of different materials, for normally incident radiation on these nano-gratings. For all nano-grating materials, the nano-grating height ‘H’ and periodicity ‘P’ are 100 nm, the spacing ‘W’ between the nanolines is 7 nm, and the refractive index of the medium surrounding the nano-grating is 1.33.
Mentions: In this paper, we have also discussed how normally incident radiation can be coupled into surface plasmons using the narrow groove plasmonic nano-gratings. Figure 8aFig. 8

Bottom Line: We present a novel surface plasmon resonance (SPR) configuration based on narrow groove (sub-15 nm) plasmonic nano-gratings such that normally incident radiation can be coupled into surface plasmons without the use of prism-coupling based total internal reflection, as in the classical Kretschmann configuration.Our calculations indicate substantially higher differential reflectance signals, on localized change of refractive index in the narrow groove plasmonic gratings, as compared to those obtained from conventional SPR-based sensing systems.Furthermore, these calculations allow determination of the optimal nano-grating geometric parameters - i. e. nanoline periodicity, spacing between the nanolines, as well as the height of the nanolines in the nano-grating - for highest sensitivity to localized change of refractive index, as would occur due to binding of a biomolecule target to a functionalized nano-grating surface.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA.

ABSTRACT
We present a novel surface plasmon resonance (SPR) configuration based on narrow groove (sub-15 nm) plasmonic nano-gratings such that normally incident radiation can be coupled into surface plasmons without the use of prism-coupling based total internal reflection, as in the classical Kretschmann configuration. This eliminates the angular dependence requirements of SPR-based sensing and allows development of robust miniaturized SPR sensors. Simulations based on Rigorous Coupled Wave Analysis (RCWA) were carried out to numerically calculate the reflectance - from different gold and silver nano-grating structures - as a function of the localized refractive index of the media around the SPR nano-gratings as well as the incident radiation wavelength and angle of incidence. Our calculations indicate substantially higher differential reflectance signals, on localized change of refractive index in the narrow groove plasmonic gratings, as compared to those obtained from conventional SPR-based sensing systems. Furthermore, these calculations allow determination of the optimal nano-grating geometric parameters - i. e. nanoline periodicity, spacing between the nanolines, as well as the height of the nanolines in the nano-grating - for highest sensitivity to localized change of refractive index, as would occur due to binding of a biomolecule target to a functionalized nano-grating surface.

Show MeSH
Related in: MedlinePlus