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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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FDTD Simulations showing EM field enhancement (at plasmon resonance wavelengths) in the narrow gaps between neighboring nanolines of a nano- gratings having 100 nm Periodicity ‘P’ and Height ‘H’, and 7 nm gap between adjacent nanolines for: (a) Silver and (b) Gold nano-gratings. In these calculations, the direction of the TM radiation incident on the nano-gratings is the ‘Z’ direction.
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g009: FDTD Simulations showing EM field enhancement (at plasmon resonance wavelengths) in the narrow gaps between neighboring nanolines of a nano- gratings having 100 nm Periodicity ‘P’ and Height ‘H’, and 7 nm gap between adjacent nanolines for: (a) Silver and (b) Gold nano-gratings. In these calculations, the direction of the TM radiation incident on the nano-gratings is the ‘Z’ direction.

Mentions: Theoretical analysis of the enhancement of EM fields inside plasmonic narrow groove nano-gratings were previously described in literature [36, 37]. We carried out FDTD calculations to show the spatial distribution of the EM fields inside the narrow groove nano-gratings (See Fig. 9Fig. 9


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

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

FDTD Simulations showing EM field enhancement (at plasmon resonance wavelengths) in the narrow gaps between neighboring nanolines of a nano- gratings having 100 nm Periodicity ‘P’ and Height ‘H’, and 7 nm gap between adjacent nanolines for: (a) Silver and (b) Gold nano-gratings. In these calculations, the direction of the TM radiation incident on the nano-gratings is the ‘Z’ direction.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

g009: FDTD Simulations showing EM field enhancement (at plasmon resonance wavelengths) in the narrow gaps between neighboring nanolines of a nano- gratings having 100 nm Periodicity ‘P’ and Height ‘H’, and 7 nm gap between adjacent nanolines for: (a) Silver and (b) Gold nano-gratings. In these calculations, the direction of the TM radiation incident on the nano-gratings is the ‘Z’ direction.
Mentions: Theoretical analysis of the enhancement of EM fields inside plasmonic narrow groove nano-gratings were previously described in literature [36, 37]. We carried out FDTD calculations to show the spatial distribution of the EM fields inside the narrow groove nano-gratings (See Fig. 9Fig. 9

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